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BioWare doubling Montreal employees
Fri, 03 Sep 2010 13:59:49 EDT - Edmonton-based BioWare is doubling the number of employees at its Montreal offices, with the ultimate goal of creating an autonomous studio that will design its own video games.
Rockies fossils yield 8 new species
Fri, 03 Sep 2010 11:50:06 EDT - A surprise fossil field at a glacier in B.C.'s Kootenay National Park contains at least eight new species that lived 505 million years ago.
1st century wall paintings restored in Jordan
Fri, 03 Sep 2010 15:33:17 EDT - British archeologists have completed conservation of rare wall paintings near the city of Petra, Jordan, that are more than 2,000 years old.
AUDIO: Technology and the great outdoors
Fri, 03 Sep 2010 14:55:57 EDT - Cellphones and GPS devices are changing people's relationship with the great outdoors - a topic explored on CBC Radio's The Current.
Fall peaches bred in Niagara
Fri, 03 Sep 2010 14:05:35 EDT - A professor at the University of Guelph in southern Ontario is developing a series of peach varieties that could continue to be available into late September.
UBC lab aims to design better traffic systems, reduce accidents
Fri, 03 Sep 2010 08:27:19 EDT - Engineers at the University of British Columbia are building what they hope will be a reliable system for predicting the likelihood of car crashes in a specific area, a development that could help save lives and cut pollution.
AUDIO: Retired chimps may face more experiments
Fri, 03 Sep 2010 14:52:48 EDT - A group of chimpanzees in New Mexico, some of them in their 50s, may be taken out of retirement to be used as research subjects.
Close ties drive online health searches: study
Fri, 03 Sep 2010 13:57:40 EDT - People looking to adopt new health practices are more likely to be influenced by close connections, including people they know well, than by social networks such as Facebook, research shows.
U.A.E. calls BlackBerry a spy tool
Fri, 03 Sep 2010 12:13:19 EDT - Worries about spying by the U.S. and Israel spurred plans to sharply limit BlackBerry services in the United Arab Emirates, Dubai's police chief said in comments that suggest a tough line in talks with the smartphone maker.
Scientists figure out magical 'banana' free kick
Fri, 03 Sep 2010 09:45:29 EDT - Thirteen years after Roberto Carlos stunned onlookers with his amazing "banana" free kick that seemed to defy the law of physics, scientists have finally worked out how he did it.
Rare red pandas born in Winnipeg
Thu, 02 Sep 2010 12:18:53 EDT - Two rare baby red pandas, born at Winnipeg's Assiniboine Park Zoo in June, are being brought out to meet the press.
Samsung launches Galaxy Tab with Kobo e-reader
Thu, 02 Sep 2010 14:46:05 EDT - Samsung has launched the Galaxy Tab, a competitor tablet computer to Apple's hit iPad, and it is shipping with some Canadian content: the Kobo e-reading application.
Hadfield named space station commander
Thu, 02 Sep 2010 22:25:07 EDT - Col. Chris Hadfield will become the first Canadian astronaut to command the International Space Station during a mission launching late in 2012.
RIM should open up user data: UN agency
Thu, 02 Sep 2010 14:29:57 EDT - The head of the United Nations telecommunications agency has urged BlackBerry maker Research in Motion to allow law enforcement agencies access to customer data.
God unnecessary to create universe: Hawking
Thu, 02 Sep 2010 09:08:42 EDT - Physicist Stephen Hawking says God wasn't necessary for the creation of the universe.

FOXNews.com

FOX News Network - We Report. You Decide.

7.0 Quake Shakes New Zealand Awake
Fri, 03 Sep 2010 20:09:46 GMT 2010-09-03T20:09:46Z -

A strong 7.0-magnitude earthquake struck close to New Zealand's second-largest city of Christchurch early Saturday local time, wreaking havoc on buildings, roads and infrastructure.


NASA Wants to Plunge a Probe Into the Sun
Fri, 03 Sep 2010 15:23:19 GMT 2010-09-03T15:23:19Z -

NASA is developing an ambitious new mission to plunge a car-sized probe directly into the sun's atmosphere, boldly going where no spacecraft has gone before.


Plants and Spiders Compete for Food, Scientists Discover
Fri, 03 Sep 2010 15:06:47 GMT 2010-09-03T15:06:47Z -

Wolf spiders and carnivorous plants called sundews may compete with each other for food in the wild, a new study finds.


Tons of Tablets Set to Challenge Apple iPad's Dominance
Fri, 03 Sep 2010 13:46:22 GMT 2010-09-03T13:46:22Z -

Samsung's first tablet computer, the Galaxy Tab, will go on sale in two weeks -- joining the Dell Streak and a slew of Google-powered pads, all trying to turn up the heat on the Apple iPad.


HP Vs Dell: the Bidding War That Ended in Spectacle
Fri, 03 Sep 2010 13:34:17 GMT 2010-09-03T13:34:17Z -

The showdown over 3Par Inc. that ended Thursday was a puzzling spectacle. It pitted two of the world's biggest technology companies against each other for control of a company that was obscure outside of technology circles and flat-out unloved on Wall Street, with a stock that was stuck around $10 for a year and a half. Why?


Nazi Bomber Found in Ocean off England
Fri, 03 Sep 2010 12:29:52 GMT 2010-09-03T12:29:52Z -

A German bomber shot down in World War II has been found 50 feet below the sea off the coast of England.


Indonesian Volcano Spews New Burst of Ash
Fri, 03 Sep 2010 12:04:04 GMT 2010-09-03T12:04:04Z -

An Indonesian volcano that was quiet for four centuries shot a new, powerful burst of hot ash more than 10,000 feet in the air Friday, sending frightened residents fleeing to safety for the second time this week.


Dragon Con to Bring Costumed Hoards to Atlanta
Fri, 03 Sep 2010 11:50:44 GMT 2010-09-03T11:50:44Z -

Don't worry if you see a Klingon strolling down the street with a mummy this weekend in Atlanta. It's just Dragon Con.


Scope Sees New Details in Sunspot Bigger Than Earth
Fri, 03 Sep 2010 11:46:26 GMT 2010-09-03T11:46:26Z -

All-seeing eye of Sauron? Cosmic sunflower? Not quite. It's actually a massive sunspot as you've never seen one before, captured in stunning high resolution.


Coast Guard Preps for Hurricane Earl With Centuries of Experience Behind It
Thu, 02 Sep 2010 20:44:01 GMT 2010-09-02T20:44:01Z -

Earl is moving up the East Coast, and the U.S. Coast Guard is getting ready, moving hundreds of thousands of tons of planes, boats and rescue gear into position. The Guard hopes for the best -- and prepares for the worst.


NASA Flies Mission Through Hurricane Earl
Thu, 02 Sep 2010 19:28:38 GMT 2010-09-02T19:28:38Z -

NASA scientists flew Thursday into Hurricane Earl to gather data about what makes some tropical storms strengthen into destructive hurricanes while most fizzle.


What's in Your Water? Probably Tiny Invisible Shrimp
Thu, 02 Sep 2010 17:32:04 GMT 2010-09-02T17:32:04Z -

Invisible shrimp could very well be living in every drop of water you drink -- but that's OK, they're nothing to worry about.


U.S. Delays Web Traffic Regulation
Thu, 02 Sep 2010 15:38:16 GMT 2010-09-02T15:38:16Z -

U.S. communications regulators on Wednesday put off a controversial decision on Internet traffic rules, giving industry and consumer groups a chance to forge a compromise while avoiding a politically sensitive issue ahead of the November elections.


To Spend Real Money on Fake Money, Go to Target
Thu, 02 Sep 2010 14:02:13 GMT 2010-09-02T14:02:13Z -

Target has begun selling gift cards for Facebook credits, letting consumers spend real money on fake money to buy gear in online apps and games such as Farmville. 


BlackBerry Should Share Users' Data, Says the U.N.
Thu, 02 Sep 2010 13:56:45 GMT 2010-09-02T13:56:45Z -

The chief of the U.N.'s telecommunications agency is urging BlackBerry's manufacturer to allow foreign law enforcement agencies access to its customers' data.


Stephen Hawking Picks Physics Over God for Big Bang
Thu, 02 Sep 2010 11:31:14 GMT 2010-09-02T11:31:14Z -

Physics was the reason for the Big Bang, not God, according to scientist Stephen Hawking.


North Carolina County Orders Evacuation of 30,000 Ahead of Earl
Wed, 01 Sep 2010 21:17:56 GMT 2010-09-01T21:17:56Z -

A hurricane warning was issued for North Carolina on Wednesday as Hurricane Earl barreled toward the East Coast packing winds of 125 mph. 


Apple Unveils New iPods, Apple TV and More
Wed, 01 Sep 2010 20:00:12 GMT 2010-09-01T20:00:12Z -

At an annual music-themed event Wednesday, Apple CEO Steve Jobs unveiled an updated streaming TV device, funky new iPods -- and a social network that's all about music.


Apple Shows Off New iPods and TV, Unveils Social Network
Wed, 01 Sep 2010 18:06:37 GMT 2010-09-01T18:06:37Z -

Apple fans Web-wide tuned in to an annual music-themed event Wednesday, where Steve Jobs unveiled an updated streaming TV device, funky new iPods -- and a social network that's all about music.


Jordan Unearths 3,000-Year-Old Iron Age Temple
Wed, 01 Sep 2010 15:11:01 GMT 2010-09-01T15:11:01Z -

Archaeologists in Jordan have unearthed a 3,000-year-old Iron Age temple with a trove of figurines of ancient deities and circular clay vessels used for religious rituals, officials said Wednesday.


Popular Science - Science

This Week in the Future, August 30-Septmber 3
Fri, 03 Sep 2010 20:30:36 +0000 -
This Week in the Future, August 30-Septmber 3 Baarbarian

Do not pass go. Do not collect $200. Just agree to a lifetime of hyper-accurate real-time location tracking. The future of incarceration is just one of our favorite posts this week.

This week in the future on PopSci:

Researchers Announce First Implantable Artificial Kidney Prototype
Fri, 03 Sep 2010 19:16:16 +0000 -
Artificial Kidney Thousands of nano-filters remove toxins from the blood, while a BioCartridge of renal tubule cells mimics the metabolic and water-balance roles of the human kidney. UCSF via ScienceDaily

An artificial kidney powered by the circulatory system could be the first implantable device to replace kidney donation and dialysis, scientists say.

Led by a University of California-San Francisco scientist, a consortium of about 10 different research teams unveiled a new artificial kidney prototype this week, saying a room-sized version has already shown promise for the sickest patients. Fabrication processes used to make silicon chips could conceivably be used to make coffee-cup-sized devices, which could take thousands of people off dialysis machines or kidney-donor waiting lists.

The multi-institutional team, led by UCSF professor Shuvo Roy, formerly of the Cleveland Clinic, is the first to demonstrate technology that could be feasibly downsized into a transplant device.

It's a two-stage system involving thousands of nanoscale filters placed in a "BioCartridge," which would remove toxins from the blood. A "HemoCartridge" bioreactor made of engineered renal tubule cells would mimic the metabolic and water-balancing roles of a real kidney. The system uses a patient's blood pressure to perform filtration without the use of pumps, according to a UCSF news release.

Currently, transplants and dialysis are the only ways to treat kidney failure. An implantable device would obviously be preferable, but so far, scientists have not been able to come up with a system that mimics everything the kidney can do.

The new system relies on the latest advances in nanotechnology and tissue generation, Roy said. He hopes to use silicon-fabrication technology to make the device small enough for transplant.

"This could dramatically reduce the burden of renal failure for millions of people worldwide, while also reducing one of the largest costs in U.S. healthcare," he said.

[ScienceDaily]

New Method Swaps Pressurized Biomass For Petroleum in Plastics, Cosmetics
Fri, 03 Sep 2010 17:00:46 +0000 -
Antifreeze via Flickr/ pinkmoose

An accidental chemistry discovery could lead to a new method for making antifreeze, moisturizer and plastic bottles out of biomass rather than petroleum, according to researchers at Iowa State University.

Professor Walter Trahanovsky was using a high-temperature chemistry process to see if he could obtain sugar derivatives from cellulose. It's based on supercritical fluids, which are heated under pressure until their fluid and gas states merge. It is not quite as exotic as it sounds - supercritical carbon dioxide is used to decaffeinate coffee.

Trahanovsky and his colleagues put cellulosic materials in alcohols and subjected them to high temperatures and pressures. They got the sugars they were looking for, but they also found something else: significant amounts of propylene glycol and ethylene glycol. This was totally unexpected, Trahanovsky said.

Anyone who has ever read a body-lotion bottle would recognize the name propylene glycol - it's a key moisturizing ingredient. It is used in a variety of products, including as a food additive. Ethylene glycol is most commonly used in antifreeze, polyester fabric and plastic bottles.

The supercritical fluid process could be a better way to obtain these materials from biomass instead of petroleum. Current biomass-refining processes require strong acids or other harmful or expensive reagents, and the processes also generate hazardous waste.

Trahanovsky said the process also produces sugar compounds that can be converted into glucose for ethanol production or other uses. The Iowa State University Research Foundation Inc. filed for a patent based on his technology.

[Iowa State University News]

NASA Solar Probe Sets Controls for the Heart of the Sun, Literally
Fri, 03 Sep 2010 15:30:45 +0000 -

In a mission to learn more about the sun's inner workings, NASA is planning to launch a specially shielded spacecraft in 2018 that will plunge into the solar atmosphere. The car-sized Solar Probe Plus will explore an area just 4 million miles from the star's surface, the last region of the solar system to be explored by humans.

NASA just announced five science experiments that will fly on the scorching probe, which will be protected by a carbon-fiber heat shield that can withstand temperatures of 2,500 degrees F.

When the probe is 4 million miles away, the solar disk will loom 23 times wider in the sky than it does on Earth.

The mission will help scientists better understand solar radiation. Improved solar storm forecasts could protect future long-distance space explorers who would not be protected by Earth's magnetic field.

The SWEAP solar wind experiment will count the electrons, protons and helium ions in the solar wind and measure their properties. It will also catch some in a special cup for analysis.

Another science mission will use a wide-field camera to take 3-D pictures of the solar wind as the spacecraft flies through it. Another will take direct measurements of the sun's magnetic fields, radio emissions and shock waves, and the one more will take an inventory of the sun's contents.

"For the very first time, we'll be able to touch, taste and smell our sun," said Lika Guhathakurta, Solar Probe Plus program scientist at NASA headquarters.

NASA's goals are to figure out why the sun's corona is several hundred times hotter than the surface and why it produces an accelerating solar wind. Scientists already have high-resolution images and data of the transition zone between the atmosphere and the surface, and the solar wind has been studied extensively - but still, no one can answer some fundamental questions about the sun's evolution. The only way to do it is to go to the source, NASA says. Here's hoping the spacecraft doesn't get burned.

[NASA]

Oil Rig Explodes in the Gulf of Mexico (Again)
Thu, 02 Sep 2010 16:04:36 +0000 -

Miss the good old days of daily oil disaster news? Worry not, for another oil rig in the Gulf of Mexico exploded this morning, leaving all 13 crew members in the water but - according to initial reports - all are alive and only one is injured. The rig is owned by Mariner Energy (somewhere a BP exec is breathing again) and is not currently producing, according to the Coast Guard. Updated. Details are sketchy right now, but rescuers are en route to the site about 80 miles south of the central Louisiana coast. We'll update as this one develops.

Update: Reuters is reporting that the Coast Guard has spotted a one-nautical-mile by 100-foot oil sheen in the water at the site of the rig explosion. The fire has been contained, but the flames have not yet been completely extinguished.

Update: USA Today now reports that the initial claim of an oil sheen by Mariner Energy cannot be confirmed by the Coast Guard, and that an aerial flyover by Mariner personnel could not locate the oil sheen reported earlier. In other good news, the fire aboard the oil platform has now been extinguished.

[NYT]

Fundamental Physics Laws Change Depending on When and Where You Are, New Study Says
Thu, 02 Sep 2010 14:57:56 +0000 -
The Early Universe A computer model of the universe at an age of about 2 billion years. Gravity causes the primordial matter to arrange itself in thin filaments. ESO

A particularly mind-bending (and controversial) physics paper surfaced in the past week that should make you feel pretty special. It seems the laws of physics can change after all, and it just so happens they're uniquely suited for us right here, right now.

The paper, recently submitted to Physical Review Letters and posted to the physics arXiv, suggests the fine structure constant is not actually constant at all. This could mean that if we were in a different place or time period, atoms would not stay together and nothing - neither planets nor people - could exist.

A team led by John Webb at the University of New South Wales, Australia, has been studying whether the fine structure constant, otherwise known as alpha, changes over time. Alpha is a special number that essentially describes the strength of the electromagnetic force. The famous physicist Richard Feynman called its value "one of the greatest damn mysteries of physics." If it is not 1/137.036, things fall apart.

If alpha was different in the past, the universe might have looked different, too, which could be determined by looking at distant interstellar gases and how they absorb light. Observations by Webb and others at the Keck Observatory in Hawaii suggest that this is exactly the case - over time, alpha has changed ever so slightly.

Competing studies did not find the same result, however, so this is still a controversial idea. But it's a fair bet Webb's follow-up is even more tendentious: He says alpha also changes over space. According to his theory, we're smack in the Goldilocks zone, where alpha is exactly the right value to make matter possible.

This paper happened because Webb and his team wanted to reexamine their Keck findings, which suggested alpha was a tiny bit smaller about 9 billion years in the past. They went to the Very Large Observatory in Chile to check it out, and were shocked by what they saw: the further they looked, the bigger alpha got. The discrepancy is even stranger given the two telescopes' positions: they are in two different hemispheres, so they look in two different directions.

So, to recap: in one direction, alpha was once smaller; in exactly the opposite direction, it was once bigger. This implies that alpha continuously varies throughout space. As Technology Review's physics blog puts it, that's a mind-blowing result. If it's true and can be verified, it could mean the universe is much larger than what we can see, and that the laws of physics vary within it.

It would not be possible for our type of life to exist in a place where alpha were any different. So here's to here and now.

[The Economist]

Future Mars Colonists Could Learn To Terraform By Studying Darwin's Methods
Thu, 02 Sep 2010 13:57:10 +0000 -
Ascension Island Charles Darwin's artificial forest captures moisture from clouds that drift over the volcanic peaks on Ascension Island. Google Earth

The father of evolution apparently played God with a tropical ecosystem 160 years ago, and the results could inform future experiments to terraform Mars, botanists say.

The BBC recounts how Charles Darwin helped build an artificial forest on Ascension Island, one of his subjects of study from his trips on the HMS Beagle. Today, the island is home to species of plants that would not naturally co-exist. Darwin and his friends put them there, and nearly two centuries later, their grand experiment is living proof that we can transform natural environments.

Originally used as an outpost to keep an eye on Napoleon in exile, Ascension Island, between South America and Africa, was a busy Atlantic waystation in Darwin's day. It had meager fresh water supplies, however, so Darwin and his botanist friend, Joseph Hooker, set out to change things.

The BBC interviews Darwin biographer David Catling, a professor at the University of Washington-Seattle, who says he believes Darwin decided to build a lush "Little England" on the volcanic island after visiting it in 1836.

Darwin's friend Hooker explored Ascension a few years later, and in 1847, Darwin convinced Hooker to get his father -- director of the Kew Gardens -- to send trees, hoping they would capture rain, prevent erosion and reduce evaporation.

Beginning in 1850 and continuing each year, ships brought an assortment of plants from botanical gardens in Europe, South Africa and Argentina, the BBC says. By the late 1870s, eucalyptus, Norfolk Island pine, bamboo, and banana had taken hold.

Today, Ascension is home to a cloud forest that would have taken millions of years to evolve naturally, according to Dave Wilkinson, an ecologist at Liverpool John Moores University in the UK.

It's proof that humans can build a fully functioning ecosystem simply through trial and error, he said. As the BBC reports, the same principle could be used in future Mars colonies: "Rather than trying to improve an environment by force, the best approach might be to work with life to help it find its own way."

Intelligent design, indeed.

As East Coast Braces For Hurricane Earl, NASA Watches From Above
Wed, 01 Sep 2010 21:21:56 +0000 -
Hurricane Earl A view of Hurricane Earl's eye, taken from the International Space Station. At the time Earl was centered just north of the Virgin Islands. NASA

East Coast residents are bracing for this monster, headed their way with 125-mph winds, as a fleet of NASA satellites and airplanes monitors its evolution.

As of Wednesday morning, Hurricane Earl was a Category 3 storm, but an especially large one. Storm-force winds extend 200 miles from its eye, seen above in a photo snapped from the International Space Station.

NASA scientists are flying airplanes into this swirling mass, measuring the hurricane's wind speeds, precipitation and more. As part of NASA's GRIP program - Genesis and Rapid Intensification Processes - a NASA DC-8 flew through Earl's eye six times as the hurricane intensified from a Category 2 to a Category 4 storm.

Meanwhile, an ISS crew member used a digital camera with a 50mm lens to take the above photo, from a much safer distance.

Climate Villain Bjørn Lomborg Does U-Turn, Says Global Warming is a $100 Billion Problem
Wed, 01 Sep 2010 18:00:27 +0000 -
Bjorn Lomborg Lomborg.com

Apparently, some tigers can change their stripes -- especially if they have books to sell. One of our favorite climate villains, the Danish economist Bjørn Lomborg, has apparently warmed to the idea of climate change, and now says it's a problem on which the world ought to spend $100 billion annually.

Lomborg's forthcoming book, Smart Solutions to Climate Change, declares that global warming is "undoubtedly one of the chief concerns facing the world today." He examines eight methods to reduce or stop it, including wave, wind, solar and nuclear power, as well as geoengineering, and advocates a carbon emissions tax to finance investment.

As the British media points out, it's a nice U-turn from a man whom the UN climate chief once compared to Adolf Hitler. In a great example of climate politics making strange bedfellows, the same UN chief, Rajendra Pachauri, provides a book-jacket endorsement: "This book provides not only a reservoir of information on the reality of human-induced climate change, but raises vital questions and examines viable options on what can be done."

In an interview with the Guardian, Lomborg explains that he reached his conclusions like any good economist: By studying the numbers. In 2004, economists at Lomborg's Copenhagen Consensus think tank were asked how they'd spend $50 billion to solve the world's problems. They ranked climate change near the bottom of the priority list, below issues like HIV and malaria. But four years later, economists tackled the question again, and interest in climate change had risen like the polar temperatures. Lomborg said this prompted him to consider new climate change policies, so global warming wouldn't languish at the bottom of the list.

Earlier this summer, we ripped Lomborg for railing against programs and treaties that aim to lessen or halt anthropogenic climate change. Now that he says it should be a top priority, we'll take him off our villain list. And give him credit for his media savvy -- the guy knows how to sell books.

[the Guardian]

Researchers Devise the First Experimental Test of Controversial, Confusing String Theory
Wed, 01 Sep 2010 16:57:03 +0000 -
Testing the Theory of Everything This is a 2-D visualization of a Calabi-Yau manifold. Some string theorists think the extra dimensions of space-time, which are predicted in string theory, may take this shape. A new study says string theory can be tested by observing the behavior of entangled quantum particles. Wikipedia

Is everything in the universe made up of vibrating one-dimensional strings? For the first time, scientists think they can concretely test string theory, the mind-blowing "theory of everything" that has dominated physics for the past two decades. It turns out that string theory predicts the behavior of entangled quantum particles, which can be tested in a lab - therefore testing string theory.

String theory elegantly reconciles the otherwise competing rules of quantum mechanics and general relativity. It's the most widely accepted unified field theory, but it remains controversial. It basically posits that electrons and quarks are not objects, but one-dimensional strings, whose oscillation gives them their observed qualities. The most fun element of string theory is the requirement that the universe has about a dozen dimensions, rather than the usual four (length, width, height and time).

M-theory, the dominant version of string theory, holds that the universe is made up of unfathomably small slices of a 2-dimensional membrane, wriggling in 11-dimensional space.

These bizarre ideas are widely accepted by many theoretical physicists, but the problem is that they can't be tested - how do you examine an 11th dimension? The field has suffered a backlash in recent years partly for this reason, as some scientists say a theory is not a theory if its predictions can't be studied in a lab.

Well, now they can, according to professor Mike Duff of the theoretical physics department at Imperial College London. He is lead author of a paper to be published tomorrow in Physical Review Letters, which explains how string theory math can be used to predict quantum entanglement.

Duff said he was at a conference in Tasmania when a colleague presented some mathematical formulas describing entanglement of multiple quantum bits. The equations looked familiar. Upon returning home, Duff checked his notebooks from a few years earlier, and realized the formulas were the same as those he developed to use string theory to describe black holes.

This is completely unexpected, he said. There is no obvious reason why the insanely complex mathematics underlying string theory can also be used to predict the behavior of entangled quantum systems.

"This may be telling us something very deep about the world we live in, or it may be no more than a quirky coincidence," he said.

Either way, it's useful, he added. Using string theory math, Duff predicted the pattern that would occur when four quantum bits are entangled with each other. This can be measured in a lab, and the results will demonstrate whether string theory actually works.

Right now, the best hope for string theory tests comes from CERN's Large Hadron Collider, which is designed to find the tiniest elementary particles that make up matter. It's theoretically possible that LHC experiments will uncover supersymmetric particles - one element of string theory - or bounce a graviton into a higher dimension, which could help prove M-theory. But testing the fuzzy math that predicts these behaviors will be much easier.

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How Websites Make You Spill Your Secrets
Fri, 03 Sep 2010 04:00:00 GMT -

People divulge more sensitive information on sites that look less safe.

Researchers at Carnegie Mellon University have found that the appearance of website has a big effect on how honestly people answer personal questions put to them by the site. But paradoxically, it turns out we're more likely to spill our secrets on websites that appear less reputable. The way a website phrases questions also affects our willingness to disclose revealing information, the researchers found.



Video App Offers Guidance While You Shoot
Fri, 03 Sep 2010 04:00:00 GMT -

NudgeCam encourages good footage by tracking faces and assessing sound quality.

If you've ever accidentally shot a video sideways, or cropped the top of someone's head out of a frame, you might be glad to know about a new cell-phone app that automatically provides shooting advice to videographers.



Blog - How To Tell Who Is Influencing Whom in a Group Discussion
Fri, 03 Sep 2010 04:10:00 GMT -

A computer model that detects who is influencing whom in a group discussion, can accurately predict who is likely to speak next

One fascinating question that occupies social scientists concerns groups discussions. The problem is to determine the nature of the interaction between individuals and in particular, who influences whom.



Blog - MapRejuice Is SETI@Home on Steroids
Fri, 03 Sep 2010 16:00:00 GMT -

Millions of Web surfers have spare computer cycles--why not use browsers to tap them?

Unless a flash ad in one of your open browser tabs has gone rogue, it's likely you've got a few spare processor cycles available on the PC you're using to read this.



Robotic Storm Tracker Gets a Big Test with Earl
Thu, 02 Sep 2010 04:00:00 GMT -

The largest-ever storm monitoring mission is now gathering scientific data that was previously impossible to get.

As Hurricane Earl barrels toward the eastern seaboard of the United States, coastal residents don't know if they should evacuate in case the storm makes landfall. They rely on forecasters analyzing computer models, but those predictions differ. A new hurricane-monitoring mission that's now underway hopes to reduce this uncertainty by gathering atmospheric and environmental storm data never before obtained.



Counting Down to Commercial Space Launches
Thu, 02 Sep 2010 04:00:00 GMT -

The next few years will see at least two new commercial spacecraft put into orbit.

A small fleet of privately developed spacecraft will head into orbit in the next few years--assuming that current levels of public and private funding can be sustained. If it happens, this will mark a new chapter in space exploration and research, as NASA comes to rely more on private companies for the technology to put manned and unmanned vehicles in space.



Transplanting Gut Microbes to Treat Disease
Thu, 02 Sep 2010 04:00:00 GMT -

Scientists examine new ways to manipulate the microorganisms within us.

Earlier this summer, scientists reported the success of an unusual medical transplant; a woman with a life-threatening Clostridium difficile infection was treated, and apparently cured, with an injection of some of her healthy husband's gut bacteria. Researchers are now exploring the effects of this type of transplant in greater detail. They hope to eventually treat a wide range of ailments--from bowel diseases to obesity, diabetes to depression--by manipulating the bacteria that live in the human gut.



Blog - The New Science of Network Archaeology
Thu, 02 Sep 2010 04:10:00 GMT -

A new way of excavating the past structure of networks reveals important information about their evolution



Blog - NASA's Blueprint for New Space Technologies
Thu, 02 Sep 2010 04:00:00 GMT -

The agency announced its latest revision but budget uncertainties in the U.S. Congress make plans moving targets.



Tiny Needles to Fight Cancer
Wed, 01 Sep 2010 04:00:00 GMT -

Researchers inject quantum dots into the skin using plastic microneedles, potentially providing a way to diagnose and treat diseases.

Using a novel laser-based technique, researchers at North Carolina State University have made arrays of tiny, hollow plastic needles that they used to insert fluorescent quantum-dot dyes into skin. Biomedical engineering professor Roger Narayan, who leads the research, says the microneedles and quantum dots, which have been tested on pigs, could be used to diagnose and treat skin cancer and other chronic diseases.



Blog - The Extraordinary Tale of Red Rain, Comets and Extraterrestrials
Wed, 01 Sep 2010 04:10:00 GMT -

For years, claims have circulated that red rain which fell in India in 2001, contained cells unlike any found on Earth. Now new evidence that these cells can reproduce is about to set the debate alive

Panspermia is the idea that life exists throughout the universe in comets, asteroids and interstellar dust clouds and that life of Earth was seeded from one or more of these sources. Panspermia holds that we are all extraterrestrials.



Blog - New Funding for Biomedical Research in Space
Wed, 01 Sep 2010 18:00:00 GMT -

The National Institute of Health announces the grants for research aboard the space station.

The National Institute of Health (NIH) has awarded the first new grants for biomedical research on the International Space Station (ISS). The grants are part of an initiative between NIH and NASA to spur research on health issues in microgravity.



Blog - Robots Take Out the Trash
Wed, 01 Sep 2010 04:00:00 GMT -

"Dustcart" finished a test run in Italy, successfully making house calls to collect garbage.

In the Italian town of Peccioli the streets are too old and narrow for garbage trucks to navigate, so residents have had to manage their own trash collection. That is, until the appearance of this summer of "Dustcart," a Segway-wheeled, sensor-equipped robot that responds to house calls to collect garbage.



Blog - Apple Shows a Facebook Rival and Apple TV 2.0
Wed, 01 Sep 2010 04:00:00 GMT -

Music-focused social network is linked to iTunes, and TV shows will rent for 99 cents.



Video - Flying Robotic Hands
Fri, 27 Aug 2010 04:00:00 GMT - The Yale Aerial Manipulator uses a flexible robotic hand to successfully grasp a range of objects while hovering.

Video - Diving into Data
Wed, 25 Aug 2010 04:00:00 GMT - A giant sphere at the University of California Santa Barbara visualizes science data in 3D, from brain scans to new molecules.

Video - How to Redesign Life
Wed, 25 Aug 2010 04:00:00 GMT - At the J. Craig Venter Institute in Rockville, MD, researchers have developed one of the most powerful methods yet for redesigning life. By editing genomes on the computer, synthesizing them in the lab, and transplanting the genomes into cells, Venter Institute researchers can speed up the process of genetic engineering. Ultimately, they want to design and create microbes that efficiently produce clean fuels, vaccines, and other products.

Video - 35 Innovators under 35
Wed, 25 Aug 2010 04:00:00 GMT - Jason Pontin, Technology Review's Editor in Chief and Publisher, explains how and why we choose our young leaders.

Video - Making Better Photonic Devices
Wed, 25 Aug 2010 04:00:00 GMT - Michelle Povinelli, a member of the 2010 TR35, explains how a fuller understanding of light’s fundamental physics can lead to better designs for telecommunications devices and solar cells.

Video - Commercializing Neurotechnology
Wed, 25 Aug 2010 04:00:00 GMT - TR35 member Mikhail Shapiro explains why he wants to develop better interfaces for the brain.

Video - Learning the Ways of the People of the Web
Wed, 25 Aug 2010 04:00:00 GMT - 2010 TR35 member Danah Boyd, a senior researcher at Microsoft Research, studies how people use social networks and makes recommendations about how companies can best use social technologies to serve their users. Recently, Boyd has been a vocal advocate for better privacy controls on social networks.

Video - How to Make Robotic Hands
Wed, 25 Aug 2010 04:00:00 GMT - Aaron Dollar, a 2010 TR35 member, demonstrates in his lab at Yale University how he makes inexpensive and flexible plastic hands that robots can use to grasp a wide range of objects.

Video - Fighting Disaster with Crowdsourcing
Wed, 25 Aug 2010 04:00:00 GMT - David Kobia, the 2010 TR35 Humanitarian of the Year, explains how Ushahidi grew from a single blog post to a sophisticated online platform that can manage crises around the world.

Video - Connecting Games with Reality
Wed, 25 Aug 2010 04:00:00 GMT - Kati London, named to the 2010 TR35, explains how she designs games that incorporate real-world data to educate players at Area/Code’s offices in New York.

Video - Engineering Viruses to Destroy Biofilms
Wed, 25 Aug 2010 04:00:00 GMT - Timothy Lu, a 2010 TR35 member, demonstrates at his lab in Boston how he is using the tools of synthetic biology to wipe out the bacterial goo that can plague humans and infest industrial equipment.

Video - Creating Online Tools for Creatives
Wed, 25 Aug 2010 04:00:00 GMT - At his startup’s headquarters in New York, Avi Muchnick, a 2010 TR35 member, explains where the inspiration for his online multimedia editing suite, Aviary, came from, and how people can use it to share work.

TrendHunter.com - Technology Trends and Gadgets

Technology Trends and Gadgets

Digital Vinyl Tracks - The Lenco L-71 Turntable Converts Oldies into MP3s (GALLERY)
Fri, 03 Sep 2010 21:31:02 GMT - The Lenco L-71 Turntable brings the 70s into the 21st century with its groovy reading and encoding capabilities. The product is complete with a belt drive turntable that can copy your old favorite bands…
Saucer-Like Sound Systems - The Korean UFO Bluetooth Speaker is Out of this World (GALLERY)
Fri, 03 Sep 2010 20:49:01 GMT - These Korean UFO Bluetooth Speakers resemble flying saucers, perfect for those obsessed with outer space. Capable of being both a sound system and an mp3 player, these Korean UFO Bluetooth speakers also…
Ocular Text Lenses - BabelFisk Glasses Turns Speech to Text Before Your Eyes (GALLERY)
Fri, 03 Sep 2010 20:22:02 GMT - Mads Hindhedes’ BabelFisk glasses takes verbal speech and translates it into readable text right before your very eyes. With speech recognition software combined with hearing aid algorithms, the result…
Urbantastic Phone Covers - Stussy and Zozotown Pair Up to Design Interesting iPhone Cases (GALLERY)
Fri, 03 Sep 2010 17:38:01 GMT - Stussy and Zozotown are collaborating to create a line of skate fashion-inspired cases for the iPhone 4 to kick off Zozotown's New Design Project Volume 2. The cases don graffiti art straight from…
Baby-Monitoring Sleepwear - Easily Check on Your Baby With the Exmobaby Biosensor Pajamas
Fri, 03 Sep 2010 16:52:01 GMT - If you are a parent who knows the hassle of baby monitors, you may appreciate these featured Exmobaby Biosensor Pajamas. These interesting Exmobaby Sensor Pajamas incorporate a baby monitor within the…
Intense Illuminating Accessories - Oleh Lighting Concepts Brighten Bodies and Bus Stops (GALLERY)
Fri, 03 Sep 2010 16:30:02 GMT - Konica Minolta and Agent have collaborated to launch OLEH Lighting Concepts as an exploration of new OLED technology applications. The team has come up with both Strip Light and Wearable concepts. This…
Computer Couch Cushions - The Plush iMac is a Must-Have for Apple Fanboys and Girls (GALLERY)
Fri, 03 Sep 2010 16:20:01 GMT - If you love Apple and their products as much as you say you do, then you will welcome the Plush iMac into your house with arms wide open. This pillow was designed by Kerry Hughes to look exactly like an…
Social Media Sustenance - The Meet Eater Plant Survives on Social Interactions With Users (GALLERY)
Fri, 03 Sep 2010 14:47:02 GMT - The first living organism beyond the occasional teenager to rely solely on social media for survival is the Meet Eater plant. That plant was a social experiment by a student at the University of Queensland…
Audio-Recording Stationary - The Rec & Play Pen by Yuri Suzuki and Oscar Diaz is Extraordinary (GALLERY)
Fri, 03 Sep 2010 13:57:01 GMT - The Rec & Play pen is an extraordinary hybrid writing tool. Essentially, it "combines sound, sight and physical movement," according to PSFK, creating the most practical piece of stationary you could ever…
Multi-Talented Thermoses - The GreenTek ‘Solar Mug’ Can Heat Coffee and Recharge Phones (GALLERY)
Fri, 03 Sep 2010 13:02:02 GMT - The GreenTek ‘Solar Mug’ is like no mug you’ve ever encountered. Not only is the thermos equipped with a temperature control to keep your coffee at your heated preference, but cold temperatures can be…
Energy-Saving Apps - The Negawatt Application Helps You Become More Energy-Efficient (GALLERY)
Fri, 03 Sep 2010 10:39:02 GMT - The Negawatt iPhone app is exactly what you need to become a green homeowner. The application is intended to help users become more energy efficient in their homes. Giving advice about the way users light…
Mangafied Resort Advertising - Ohnoya Hotel Says Yes to 'Love Plus' (VIDEO)
Fri, 03 Sep 2010 08:13:01 GMT - It seems like the Ohnoya Hotel in Atami, Japan, has taken a strong interest in the virtual dating game 'Love Plus,' and is target men with virtual significant others. Putting a new spin on the virtual…
Animal Flash Drive Bling - Swarovski and Philips Make Crystallized Animal USBs (GALLERY)
Fri, 03 Sep 2010 07:16:01 GMT - Swarovski and Philips have teamed up again to create USBs for the geeky-glamorous. However, this collection is geared towards animal-lovers. Who wouldn’t want one of these adorable little animal USBs?…
Ghastly Princess Stickers - The Zombie Snow White iPad Decal is Truly Frightening (GALLERY)
Fri, 03 Sep 2010 05:46:01 GMT - Things get horrifically interesting with the zombie Snow White iPad decal. 'Stickerman' created this piece of decor to spice up the classic cute and lovable decal pieces. Like all decals for Apple products,…
10 Innovative Mousetrap Designs - From Designer Moustraps to Extreme Pest Control (CLUSTER)
Fri, 03 Sep 2010 05:30:01 GMT - If you have mice scurrying about your household, you need to check out these innovative mousetrap designs. These mousetraps are sure to rid you of rodents in a quick and efficient way. Why monitor your…
Arcade Piggy Banks - The Arcade Machine Money Box is a Playable Way to Save Your Pennies (GALLERY)
Fri, 03 Sep 2010 04:56:02 GMT - The Arcade Machine Money Box has to be one of the coolest and most interactive piggy banks ever created. This piggy bank is shaped like an arcade machine, and it even lets you play a mini-arcade game every…
Witty Vending Machines - These Juicy Drench Dispensers Will Take Your Brain Power as Cash (VIDEO)
Fri, 03 Sep 2010 04:41:02 GMT - These Juicy Drench vending machines are 100% percent free of monetary charge. However, it does require some thinking. Substituting your correct answers as a form of payment, the design is promoting the…
Dual Threat Headphones - The Dubnium Headphone Speakers Split Apart to Let Everyone Listen (VIDEO)
Fri, 03 Sep 2010 02:08:01 GMT - Dubnium headphone speakers are the perfect headphones for people who feel like to share their taste in music while they're out and about. These headphones split apart into two speakers, instantly turning…
Tacofied Album Covers - Album Tacos Mixes Tasty Mexican Treats with Classic Album Art (GALLERY)
Thu, 02 Sep 2010 22:30:01 GMT - Tacos and great music collide in the 'Album Tacos' photoblog. This photoblog features classic album art with a taco added for good effect. What makes Album Tacos so awesome is how natural these tacos…
Futuristic Flying Scooters - The 'Machine-Fly' Prototype Makes for Motor- Minus the Cycle (GALLERY)
Thu, 02 Sep 2010 20:56:01 GMT - With his prototype for the 'Machine-Fly' flying motorcycle, inventor and designer Gonzalo Guerrero will see that we'll soon become 21st century kids in the manner that the Jetsons producers predicted.…
Toddler Touchscreens - Sprint Firsts in Hi-Tech Development Tools (THTV)
Thu, 02 Sep 2010 19:56:01 GMT - Interactive tables, iPad learning apps and mini laptops. Today we hunt: TODDLER TOUCHSCREENS – Sprint Firsts in hi-tech development tools. While usually thought of as adult-only technology, touchscreen…
Static-Charged Bulletin Boards - Stix the Electrostatic Noticeboard Lets you Tack Things up Easily (VIDEO)
Thu, 02 Sep 2010 18:58:01 GMT - Stix the Electrostatic Noticeboard was designed by Jonathan Jordan. A finalist in the 2010 James Dyson Award competition, this board reduces the need for cork, staples, thumbtacks and magnets because this…
Protective Antenna Drops - iClearfix for the iPhone 4 Antenna Decreases Signal Problems
Thu, 02 Sep 2010 18:47:02 GMT - iClearfix is the solution to the iPhone 4 antenna issue. It's a liquid that adds a clear, non-conducting layer over the antenna gap on the affected side of the iPhone 4. iClearfix is low cost and its…
Nutty Plastics - NEC Makes Cashew-Based Bioplastics for Use in Electronics
Thu, 02 Sep 2010 16:39:02 GMT - NEC, the Japanese electronics company, has used an extract from cashew nut shells and plant cellulose to create cashew-based bioplastics that are stronger than corn starch-based bioplastics. Not only…
Computerized Surfboards - Students Build the Ultimate Board Using a Computer-Equipped Version (GALLERY)
Thu, 02 Sep 2010 15:00:02 GMT - Four students at the University of California San Diego have created a computer-equipped surfboard in an attempt to design the ultimate surfboard. The surfboard is equipped with an on-board computer and…
30 Unusual Watches - A Compilation of Timepieces for Avid Horologists (CLUSTER)
Thu, 02 Sep 2010 14:40:02 GMT - Horologists study clocks, chronometers and watches and this compilation of timepieces for avid horologists will get anyone’s mind ticking with the possibilities of wrist-worn clocks. So, enjoy a look…
Seaworthy USBs - The USB Battleship Brings Five Extra USB Ports to the Fight
Thu, 02 Sep 2010 13:58:02 GMT - Turn the tide of battle against a lack of USB ports with the USB Battleship. This battleship comes equipped with five USB ports, instantly changing your computer from a frigate to a carrier. The USB Battleship…
Single-Handed Timepieces - 'One Hand Watches' by Raphael Ickler is a Unique Accessory
Thu, 02 Sep 2010 12:31:01 GMT - Ever wonder how you can tell time without two hands? These 'One Hand Watches' by Raphael Ickler figured out the answer to that problem. Ickler is a German-based designer who came up with this concept.…
42 Tech Innovations for the Blind - From Blind-Aiding Radar to Braille Book Readers (CLUSTER)
Thu, 02 Sep 2010 11:09:02 GMT - As the world becomes more and more technologically advanced, we must think about how to adapt this ever-evolving situation to suit the needs of the disabled. These tech innovations for the blind show…
Mini Tech Holders - The Padfoot iPad Stand Holds Your Toy up Easily (GALLERY)
Thu, 02 Sep 2010 09:02:01 GMT - Michel Cornelissen has created the Padfoot iPad Stand (Cornelissen is also the creator of the iPod Shuffle Necklace). Allowing your iPad to sit whichever way it would like, the Padfoot iPad Stand weighs…

Virtual Journal of Nanoscale Science & Technology

Virtual Journal of Nanoscale Science & Technology

Hot Brownian Motion
Daniel Rings, Romy Schachoff, Markus Selmke, Frank Cichos, and Klaus Kroy
We derive the Markovian description for the nonequilibrium Brownian motion of a heated nanoparticle in a simple solvent with a temperature-dependent viscosity. Our analytical results for the generalized fluctuation-dissipation and Stokes-Einstein relations compare favorably with measurements of lase ... [Phys. Rev. Lett. 105, 090604 ] published .
Structure of the quasi-one-dimensional Si(553)-Au surface: Gold dimer row and silicon honeycomb chain
Wolfgang Voegeli, Toru Takayama, Tetsuroh Shirasawa, Makoto Abe, Kimitaka Kubo et al.
The Si(553)-Au surface consists of a periodic array of single steps and (111) terraces with a quasi-one-dimensional electronic structure. In this paper, the determination of the atomic structure of this surface with x-ray diffraction is reported. The gold coverage of the surface was measured to be 0 ... [Phys. Rev. B 82, 075426 ] published .
Hydrogen storage cycling of MgH thin film nanocomposites catalyzed by bimetallic Cr Ti
Beniamin Zahiri, Babak Shalchi Amirkhiz, and David Mitlin
We examine hydrogen sorption cycling of 1.5 [mu]m thick magnesium thin films containing a bimetallic chromium titanium catalyst. At 200 degrees C these nanocomposites absorb 5 wt % hydrogen in several seconds, and desorb in 1020 minutes. In several compositions, there is negligible hydrogenation ... [Appl. Phys. Lett. 97, 083106 (2010)] published Thu Aug 26, 2010.
Effects of surface chemistry on thermal conductance at aluminumdiamond interfaces
Kimberlee C. Collins, Shuo Chen, and Gang Chen
Synthetic diamond has potential as a heat spreading material in small-scale devices. Here, we report thermal conductance values at interfaces between aluminum and diamond with various surface terminations over a range of temperatures from 88 to 300 K. We find that conductance at oxygenated diamond i ... [Appl. Phys. Lett. 97, 083102 (2010)] published Mon Aug 23, 2010.
Crystal-induced effects at crystal/amorphous interfaces: The case of SiN/SiO
Weronika Walkosz, Robert F. Klie, Serdar Ogut, Biljana Mikijelj, Stephen J. Pennycook et al.
We reveal the presence of atomic short-range ordering at the interface between crystalline beta-SiN and amorphous SiO using aberration-corrected scanning transmission electron microscopy. We show that the first atomic layers of the amorphous SiO film reconstruct taking on the crystalline form of SiN ... [Phys. Rev. B 82, 081412 ] published .
CuInS quantum dots synthesized by a solvothermal route and their application as effective electron acceptors for hybrid solar cells
Wenjin Yue, Shikui Han, Ruixiang Peng, Wei Shen, Hongwei Geng et al.
This paper describes a solvothermal approach to synthesize CuInS quantum dots (QDs) and demonstrates their application as a potential electron accepting material for polymer-based hybrid solar cells, for the first time. The CuInS QDs with a size of 24 nm are synthesized by the solvothermal method wi ... [J. Mater. Chem. 20, 7570 (2010)] published Wed Aug 25, 2010.
Synthesis of uniform microporous polymer nanoparticles and their applications for hydrogen storage
Buyi Li, Xin Huang, Liyun Liang, and Bien Tan
This work is aimed at producing uniform microporous polymer nanoparticles (MPNs) and studying their hydrogen storage properties. Synthesis of vinylbenzyl chloride (VBC)/divinylbenzene (DVB) copolymers by emulsion polymerization yield fairly uniform gel-type precursor nanoparticles and the particle s ... [J. Mater. Chem. 20, 7444 (2010)] published Wed Aug 25, 2010.
Versatile approach to synthesis of 2-D hexagonal ultra-large-pore periodic mesoporous organosilicas
Manik Mandal and Michal Kruk
Periodic mesoporous organosilicas (PMOs) with methylene (CH), ethylene (CHCH), ethenylene (CH[double bond, length as m-dash]CH) and phenylene (CH) framework groups were synthesized with 2-dimensional hexagonal structures of very large cylindrical mesopores. A combination of a commercially available ... [J. Mater. Chem. 20, 7506 (2010)] published Wed Aug 25, 2010.
Novel high-performance nanohybrid polyelectrolyte membranes based on bio-functionalized montmorillonite for fuel cell applications
Mohammad Mahdi Hasani-Sadrabadi, Erfan Dashtimoghadam, Fatemeh S. Majedi, Kourosh Kabiri, Nassir Mokarram et al.
This study is concerned with electrochemical investigation of novel high-performance proton exchange membranes based on bio-functionalized montmorillonite and Nafion[registered sign]. It was found that the incorporation of 2 wt% BMMT into Nafion[registered sign] polyelectrolyte matrix results in sig ... [Chem. Commun. 46, 6500 (2010)] published Wed Aug 25, 2010.
Multicomponent protein patterning of material surfaces
Ramakrishnan Ganesan, Karl Kratz, and Andreas Lendlein
Micro- and nano-scale protein patterns have gained significant technological interest. While certain techniques for single-component protein patterning are well-established, multicomponent protein patterning approaches are a current topic of intensive research, which might enable complex biosensor s ... [J. Mater. Chem. 20, 7322 (2010)] published Wed Aug 25, 2010.
Vesicular assemblies of modified Mn single molecular magnets
Wen Li, Bao Li, Yinglin Wang, Jing Zhang, Shan Wang et al.
Fatty acid modified Mn derivatives can self-assembly into vesicular structures in organic media. The vesicular assemblies have a sandwich structure with Mn cluster separated by two alkyl chain layers. ... [Chem. Commun. 46, 6548 (2010)] published Wed Aug 25, 2010.
Periodic mesoporous titanium phosphonate hybrid materials
Tian-Yi Ma, Xiu-Zhen Lin, and Zhong-Yong Yuan
Periodic mesoporous titanium phosphonate materials (PMTP-1) with bridged-organic groups inside the framework are synthesized by an autoclaving process combined with the evaporation-induced self-assembly (EISA) strategy, with the assistance of surfactant Brij 56 (CEO). Sodium salt of ethylene diamine ... [J. Mater. Chem. 20, 7406 (2010)] published Wed Aug 25, 2010.
An Adaptable Peptide-Based Porous Material
J. Rabone, Y.-F. Yue, S. Y. Chong, K. C. Stylianou, J. Bacsa et al.
Porous materials find widespread application in storage, separation, and catalytic technologies. We report a crystalline porous solid with adaptable porosity, in which a simple dipeptide linker is arranged in a regular array by coordination to metal centers. Experiments reinforced by molecular dynam ... [Science 329, 1053 ] published .
Erratum: Entanglement and density-functional theory: Testing approximations on Hooke's atom [Phys. Rev. B 77, 205122 (2008)]
J. P. Coe, A. Sudbery, and I. D'Amico
Abstract not available. [Phys. Rev. B 82, 089902 ] published .
A quantum dot based bright source of entangled photon pairs operating at 53 K
A. Dousse, J. Suffczynski, O. Krebs, A. Beveratos, A. Lemaitre et al.
The exciton and biexciton lines of a single quantum dot are deterministically coupled to the optical modes of a photonic molecule. The resonance between the quantum dot emission lines and the molecule cavity modes is reached at 53 K. The device operates as a very bright source of entangled photon pa ... [Appl. Phys. Lett. 97, 081104 (2010)] published Mon Aug 23, 2010.
Maximal violation of a bipartite three-setting, two-outcome Bell inequality using infinite-dimensional quantum systems
Karoly F. Pal and Tamas Vertesi
The I inequality is the simplest bipartite two-outcome Bell inequality beyond the Clauser-Horne-Shimony-Holt (CHSH) inequality, consisting of three two-outcome measurements per party. In the case of the CHSH inequality the maximal quantum violation can already be attained with local two-dimensional ... [Phys. Rev. A 82, 022116 ] published .
Magnetic field sensors using 13-spin cat states
Stephanie Simmons, Jonathan A. Jones, Steven D. Karlen, Arzhang Ardavan, and John J. L. Morton
Measurement devices could benefit from entangled correlations to yield a measurement sensitivity approaching the physical Heisenberg limit. Building upon previous magnetometric work using pseudoentangled spin states in solution-state NMR, we present two conceptual advancements to better prepare and ... [Phys. Rev. A 82, 022330 ] published .
Cotunneling in pairs of coupled flux qubits
T. Lanting, R. Harris, J. Johansson, M. H. S. Amin, A. J. Berkley et al.
We report measurements of macroscopic resonant tunneling between the two lowest energy states of a pair of magnetically coupled rf-superconducting quantum interference device flux qubits. This technique provides both a direct means of measuring the energy gap of the two-qubit system and a method for ... [Phys. Rev. B 82, 060512 ] published .
Quantum Interference and Entanglement Induced by Multiple Scattering of Light
J. R. Ott, N. A. Mortensen, and P. Lodahl
We report on the effects of quantum interference induced by the transmission of an arbitrary number of optical quantum states through a multiple-scattering medium. We identify the role of quantum interference on the photon correlations and the degree of continuous variable entanglement between two o ... [Phys. Rev. Lett. 105, 090501 ] published .
Quantum Correlations in Spin Chains at Finite Temperatures and Quantum Phase Transitions
T. Werlang, C. Trippe, G. A. P. Ribeiro, and Gustavo Rigolin
We compute the quantum correlation [quantum discord (QD)] and the entanglement (EOF) between nearest-neighbor qubits (spin-1/2) in an infinite chain described by the Heisenberg model (XXZ Hamiltonian) at finite temperatures. The chain is in the thermodynamic limit and thermalized with a reservoir at ... [Phys. Rev. Lett. 105, 095702 ] published .
Importance of electron-electron interactions in the RKKY coupling in graphene
Annica M. Black-Schaffer
We show that the carrier-mediated exchange interaction, the so-called Ruderman-Kittel-Kasuya-Yoshida (RKKY) coupling, between two magnetic impurity moments in graphene is significantly modified in the presence of electron-electron (el-el) interactions. Within the mean-field approximation of the Hubb ... [Phys. Rev. B 82, 073409 ] published .
Thermal annealing-induced vertical phase separation of copper phthalocyanine: Fullerene bulk heterojunction in organic photovoltaic cells
H. X. Wei, J. Li, Z. Q. Xu, Y. Cai, J. X. Tang et al.
The effect of thermal annealing treatment on the morphology change in bulk heterojunction (BHJ) in organic photovoltaic cells was studied by photoemission spectroscopy. The results reveal that vertical phase separation upon annealing occurs in typical BHJ layer formed between planar molecule CuPc an ... [Appl. Phys. Lett. 97, 083302 (2010)] published Tue Aug 24, 2010.
Selective electroless coating of palladium nanoparticles on metallic single-walled carbon nanotube
Yiyu Feng, Peng Lv, Xuequan Zhang, Yu Li, and Wei Feng
The selective electroless coating of palladium (Pd) nanoparticles on metallic single-walled carbon nanotube (SWNT) was studied. The remarkable increase in conductivity of SWNT/Pd films up to fourfold higher than pure SWNT was due to p-type doping and Ohmic contact. Metallic behavior of SWNT/Pd-Field ... [Appl. Phys. Lett. 97, 083101 (2010)] published Mon Aug 23, 2010.
Tailoring point electron sources of individual carbon nanotubes
Yung-Chang Lin, Cheng-Da Wu, and Po-Wen Chiu
We describe a technique for the fabrication of individual carbon nanotube electron field emitters on silicon substrates, with well-defined tunneling geometries and robust metal contacts. The suspended nanotube emitters have been produced by edge lithography on cleaved silicon substrate in conjunctio ... [Appl. Phys. Lett. 97, 073119 (2010)] published Fri Aug 20, 2010.
Enhancement of the short circuit current in organic photovoltaic devices with microcavity structures
Jane Lee, Sei-Yong Kim, Changsoon Kim, and Jang-Joo Kim
We demonstrate that the use of a microcavity structure can overcome the trade-off between exciton diffusion and optical absorption in planar heterojunction organic photovoltaic cells. Optical simulation based on the copper phthalocyanine (CuPc)-fullerene donor-acceptor system showed that the microca ... [Appl. Phys. Lett. 97, 083306 (2010)] published Tue Aug 24, 2010.
Optical transitions in semiconducting zigzag carbon nanotubes with small diameters: A first-principles broad-range study
Saloome Motavas, Andre Ivanov, and Alireza Nojeh
We study all possible band-to-band transitions between 12 valence and 16 conduction bands of (8,0), (10,0), and (7,0) nanotubes and calculate the corresponding dipole moments using first-principles methods in a wide ultraviolet-visible-infrared range of photon energies. The goal is to investigate th ... [Phys. Rev. B 82, 085442 ] published .
Dynamic terahertz polarization in single-walled carbon nanotubes
X. L. Xu, P. Parkinson, K.-C. Chuang, M. B. Johnston, R. J. Nicholas et al.
We have investigated the anisotropic dynamic dielectric response of aligned and well-isolated single-walled carbon nanotubes using optical-pump terahertz (THz)-probe techniques. The polarization anisotropy measurements demonstrate that the THz radiation interacts only with radiation polarized parall ... [Phys. Rev. B 82, 085441 ] published .
Electronic structures of boron nitride nanotubes subjected to tension, torsion, and flattening: A first-principles DFT study
Yusuke Kinoshita and Nobutada Ohno
Electronic structures of (6,0), (8,0), and (10,0) single-walled boron nitride nanotubes (SWBNNTs) subjected to tension, torsion, and flattening are investigated using first-principles calculations. Energy bands and charge distributions of the SWBNNTs are calculated within the density-functional theo ... [Phys. Rev. B 82, 085433 ] published .
Inelastic neutron scattering of a quantum translator-rotator encapsulated in a closed fullerene cage: Isotope effects and translation-rotation coupling in H@C and HD@C
A. J. Horsewill, S. Rols, M. R. Johnson, Y. Murata, M. Murata et al.
We report an inelastic neutron-scattering (INS) investigation of coupled quantum translation and rotation of hydrogen molecules trapped inside the closed isotropic cages of C. The low-lying states that characterize the translation-rotation manifold of the hydrogen molecules are accurately determined ... [Phys. Rev. B 82, 081410 ] published .
First-principles calculations of carbon clathrates: Comparison to silicon and germanium clathrates
Damien Connetable
We employ state-of-the-art first-principles calculations based on density-functional theory and density-functional perturbation theory to investigate relevant physical properties and phase diagram of the free guest type-I (X-46) and type-II (X-34) carbon clathrates. Their properties and those of sil ... [Phys. Rev. B 82, 075209 ] published .
Carbon nanotube initiated formation of carbon nanoscrolls
Zhao Zhang and Teng Li
The unique topology and exceptional properties of carbon nanoscrolls (CNSs) have inspired unconventional nanodevice concepts, yet the fabrication of CNSs remains rather challenging. Using molecular dynamics simulations, we demonstrate the spontaneous formation of a CNS from graphene on a substrate, ... [Appl. Phys. Lett. 97, 081909 (2010)] published Thu Aug 26, 2010.
Maximizing the open-circuit voltage of polymer: Fullerene solar cells
J. C. Bijleveld, R. A. M. Verstrijden, M. M. Wienk, and R. A. J. Janssen
The open-circuit voltage (V) of bulk heterojunction solar cells based on polymers and fullerene derivatives is limited to ~1.15 V by the optical band gap of the fullerene of ~1.75 eV and the required 0.6 eV offset for efficient charge generation. In practice this limit has not yet been reached. We ... [Appl. Phys. Lett. 97, 073304 (2010)] published Fri Aug 20, 2010.
Coherent Nonlinear Optical Response of Graphene
E. Hendry, P. J. Hale, J. Moger, A. K. Savchenko, and S. A. Mikhailov
We investigate the nonlinear optical properties of graphene flakes using four-wave mixing. The corresponding third-order optical susceptibility is found to be remarkably large and only weakly dependent on the wavelength in the near-infrared frequency range. The magnitude of the response is in good a ... [Phys. Rev. Lett. 105, 097401 ] published .
Electron-electron interactions in decoupled graphene layers
Rosario E. V. Profumo, Marco Polini, Reza Asgari, Rosario Fazio, and A. H. MacDonald
Multilayer graphene on the carbon face of silicon carbide is an intriguing electronic system which typically consists of a stack of ten or more layers. Rotational stacking faults in this system dramatically reduce interlayer coherence. In this paper we report on the influence of interlayer interacti ... [Phys. Rev. B 82, 085443 ] published .
Probing the electrical anisotropy of multilayer graphene on the Si face of 6H-SiC
B. Jouault, B. Jabakhanji, N. Camara, W. Desrat, A. Tiberj et al.
We studied the in-plane magnetoresistance R(B,T) anisotropy in epitaxial multilayer graphene films grown on the Si face of a 6H-SiC substrate that originates from steplike morphology of the SiC substrate. To enhance the anisotropy, a combination of argon atmosphere with graphite capping was used dur ... [Phys. Rev. B 82, 085438 ] published .
Electrical conductivity in graphene with point defects
Yuriy V. Skrypnyk and Vadim M. Loktev
The electrical conductivity of graphene containing point defects is studied within the binary alloy model in its dependence on the Fermi-level position at the zero temperature. It is found that the minimal conductivity value does not have a universal character and corresponds to the impurity resonan ... [Phys. Rev. B 82, 085436 ] published .
DNA-decorated graphene chemical sensors
Ye Lu, B. R. Goldsmith, N. J. Kybert, and A. T. C. Johnson
Graphene is a two-dimensional material with exceptional electronic properties and enormous potential for applications. Graphene's promise as a chemical sensor material has been noted but there has been little work on practical chemical sensing using graphene, and in particular, how chemical function ... [Appl. Phys. Lett. 97, 083107 (2010)] published Thu Aug 26, 2010.
Reversible modifications of linear dispersion: Graphene between boron nitride monolayers
J. Slawinska, I. Zasada, P. Kosinski, and Z. Klusek
Electronic properties of the graphene layer sandwiched between two hexagonal boron nitride sheets have been studied using the first-principles calculations and the minimal tight-binding model. It is shown that for the ABC-stacked structure in the absence of external field the bands are linear in the ... [Phys. Rev. B 82, 085431 ] published .
Effects of release holes on microscale solidsolid phononic crystals
Y. M. Soliman, M. F. Su, Z. C. Leseman, C. M. Reinke, I. El-Kady et al.
Solidsolid phononic crystals exhibit wider band gaps than those observed with airsolid phononic crystals. For micromachined phononic crystal devices it is advantageous to release the phononic crystal to avoid propagation losses. In a solidsolid phononic crystal operating in the low megahertz range, ... [Appl. Phys. Lett. 97, 081907 (2010)] published Wed Aug 25, 2010.
Three-dimensional large-scale microfluidic integration by laser ablation of interlayer connections
Jens Huft, Daniel J. Da Costa, David Walker, and Carl L. Hansen
Multilayer Soft Lithography (MSL) is a robust and mature fabrication technique for the rapid prototyping of microfluidic circuits having thousands of integrated valves. Despite the success and wide application of this method, it is fundamentally a planar fabrication technique which imposes serious d ... [Lab Chip 10, 2358 (2010)] published Wed Aug 25, 2010.
A microfluidic platform for probing small artery structure and function
Axel Gunther, Sanjesh Yasotharan, Andrei Vagaon, Conrad Lochovsky, Sascha Pinto et al.
Although pathologic changes to the structure and function of small blood vessels are hallmarks of various cardiovascular diseases, limitations of conventional investigation methods (i.e. pressure myography) have prohibited a comprehensive understanding of the underlying mechanisms. We developed a mi ... [Lab Chip 10, 2341 (2010)] published Wed Aug 25, 2010.
Suspended nanoparticle crystal (S-NPC): A nanofluidics-based, electrical read-out biosensor
Yinhua Lei, Fei Xie, Wei Wang, Wengang Wu, and Zhihong Li
Here we report an approach utilizing a suspended nanoparticle crystal (S-NPC) as an electrical read-out biosensor based on a nanofluidic electrokinetics principle. As a preliminary demonstration, streptavidin-modified S-NPC with a particle diameter of 520 nm was used to detect biotin in a PBS buffer ... [Lab Chip 10, 2338 (2010)] published Wed Aug 25, 2010.
Multiactuation complementary metal-oxide semiconductor radio frequency MEMS switch
Chiung-I Lee, Chih-Hsiang Ko, Tsun-Che Huang, and Feng-Chia Hsu
A complementary metal-oxide semiconductor (CMOS)-compatible, capacitive, shunt-type radio frequency MEMS switch design is demonstrated. The switch is actuated by an electrothermal actuator and an electrostatic actuator at the same time, and the switching status is latched by electrostatic force only ... [J. Micro/Nanolith. MEMS MOEMS 9, 033008 (2010)] published Thu Aug 26, 2010.
Microfluidic perfusion system for culturing and imaging yeast cell microarrays and rapidly exchanging media
Maryam Mirzaei, Mateu Pla-Roca, Roozbeh Safavieh, Elena Nazarova, Mohammadali Safavieh et al.
High resolution live cell microscopy is increasingly used to detect cellular dynamics in response to drugs and chemicals, but it depends on complex and expensive liquid handling devices that have limited its wider adoption. Here, we present a microfluidic perfusion system that is built without using ... [Lab Chip 10, 2449 (2010)] published Wed Aug 25, 2010.
A dynamic microarray device for paired bead-based analysis
Tetsuhiko Teshima, Hirotaka Ishihara, Kosuke Iwai, Aki Adachi, and Shoji Takeuchi
In this study, we have developed a meander-shaped dynamic microfluidic technology that allows us to pair two different types of microbeads in a trapping site. The dynamic microfluidic technology comprises implemented modifications of a conventional dynamic microarray design such as: (i) the combinat ... [Lab Chip 10, 2443 (2010)] published Wed Aug 25, 2010.
Droplet-based microfluidic system for multicellular tumor spheroid formation and anticancer drug testing
Linfen Yu, Michael C. W. Chen, and Karen C. Cheung
Creating multicellular tumor spheroids is critical for characterizing anticancer treatments since it may provide a better model than monolayer culture of tumor cells. Moreover, continuous dynamic perfusion allows the establishment of long term cell culture and subsequent multicellular spheroid forma ... [Lab Chip 10, 2424 (2010)] published Wed Aug 25, 2010.
Thermally compensated aluminum nitride Lamb wave resonators for high temperature applications
Chih-Ming Lin, Ting-Ta Yen, Valery V. Felmetsger, Matthew A. Hopcroft, Jan H. Kuypers et al.
In this letter, temperature compensation for aluminum nitride (AlN) Lamb wave resonators operating at high temperature is presented. By adding a compensating layer of silicon dioxide (SiO), the turnover temperature can be designed for high temperature operation by varying the normalized AlN film thi ... [Appl. Phys. Lett. 97, 083501 (2010)] published Mon Aug 23, 2010.
Optical lattices with micromechanical mirrors
K. Hammerer, K. Stannigel, C. Genes, P. Zoller, P. Treutlein et al.
We investigate a setup where a cloud of atoms is trapped in an optical lattice potential of a standing-wave laser field which is created by retroreflection on a micromembrane. The membrane vibrations itself realize a quantum mechanical degree of freedom. We show that the center-of-mass mode of atoms ... [Phys. Rev. A 82, 021803 ] published .
High aspect ratio nanochannel machining using single shot femtosecond Bessel beams
M. K. Bhuyan, F. Courvoisier, P. A. Lacourt, M. Jacquot, R. Salut et al.
We report high aspect ratio nanochannel fabrication in glass using single-shot femtosecond Bessel beams of sub-3 [mu]J pulse energies at 800 nm. We obtain near-parallel nanochannels with diameters in the range 200800 nm, and aspect ratios that can exceed 100. An array of 230 nm diameter channels wi ... [Appl. Phys. Lett. 97, 081102 (2010)] published Mon Aug 23, 2010.
The Fano resonance in plasmonic nanostructures and metamaterials
Boris Luk'yanchuk, Nikolay I. Zheludev, Stefan A. Maier, Naomi J. Halas, Peter Nordlander et al.
Since its discovery, the asymmetric Fano resonance has been a characteristic feature of interacting quantum systems. The shape of this resonance is distinctively different from that of conventional symmetric resonance curves. Recently, the Fano resonance has been found in plasmonic nanoparticles, ph ... [Nature Mater. 9, 707 (2010)] published Wed Aug 25, 2010.
Impact of nitrogen incorporation on pseudomorphic site-controlled quantum dots grown by metalorganic vapor phase epitaxy
V. Dimastrodonato, L. O. Mereni, G. Juska, and E. Pelucchi
We report on some surprising optical properties of diluted nitride InGaAsN/GaAs (epsilon<<1) pyramidal site-controlled quantum dots, grown by metalorganic vapor phase epitaxy on patterned GaAs (111)B substrates. Microphotoluminescence characterizations showed antibinding exciton/biexciton behavior, ... [Appl. Phys. Lett. 97, 072115 (2010)] published Fri Aug 20, 2010.
Charge noise at Cooper-pair resonances
P. G. Kirton, M. Houzet, F. Pistolesi, and A. D. Armour
We analyze the charge dynamics of a superconducting single-electron transistor (SSET) in the regime where charge transport occurs via Cooper-pair resonances. Using an approximate description of the system Hamiltonian, in terms of a series of resonant doublets, we derive a Born-Markov master equation ... [Phys. Rev. B 82, 064519 ] published .
Thermal trimming and tuning of hydrogenated amorphous silicon nanophotonic devices
Shankar Kumar Selvaraja, Wim Bogaerts, Dries VanThourhout, and Marc Schaekers
Deposited silicon and, in particular, hydrogenated amorphous silicon forms an attractive alternative platform for realizing compact photonic integrated circuits. In this paper we report on trimming (toward lower wavelengths) and tuning (toward higher wavelengths) of photonic devices through a suitab ... [Appl. Phys. Lett. 97, 071120 (2010)] published Fri Aug 20, 2010.
Coupling optical and electrical gating for electronic readout of quantum dot dynamics
Smitha Vasudevan, Kamil Walczak, and Avik W. Ghosh
We explore the coherent transfer of electronic signatures from a strongly correlated, optically gated nanoscale quantum dot to a weakly interacting, electrically backgated microscale channel. In this unique side-coupled T geometry for transport, we predict a mechanism for detecting Rabi oscillations ... [Phys. Rev. B 82, 085324 ] published .
Optical orientation of a single Mn spin in a quantum dot: Role of carrier spin relaxation
Lukasz Cywinski
In order to explain the recently observed phenomenon of optical orientation of a single Mn spin residing inside a CdTe quantum dot, a process of Mn spin relaxation with characteristic time scale of tens of nanosecond had been invoked. We show that after taking into account the mixing of states of th ... [Phys. Rev. B 82, 075321 ] published .
Ultralong-range Casimir-Lifshitz forces mediated by nanowire materials
Stanislav I. Maslovski and Mario G. Silveirinha
Here, we show that the Casimir-Lifshitz force (either attractive or repulsive) between two planar material slabs embedded in a dense array of silver nanowires is an ultralong-range force that decays with the separation of the bodies, a, as 1/a, whereas in an isotropic background it decays as 1/a. It ... [Phys. Rev. A 82, 022511 ] published .
Synthesis of Phosphor Photonic Crystals by Self-Assembly of SiO/YO:Tb Core/Shell Particles and Its Photoluminescence Properties
Hyoung Sun Yoo, Sung Wook Kim, and Duk Young Jeon
The monodisperse spherical SiO/YO:Tb core/shell particles were prepared by a heterogeneous precipitation coating of the phosphor shell on the surface of the core particles. The shell thickness and the calculated crystallite size were increased with the core size and, thus, the photoluminescence (PL) ... [J. Electrochem. Soc. 157, J358 (2010)] published Wed Aug 25, 2010.
Influence of Mn doping on structural, optical, and magnetic properties of ZnMnO nanorods
The-Long Phan, S. C. Yu, R. Vincent, H. M. Bui, T. D. Thanh et al.
We prepared ZnMnO nanorods by thermal diffusion. These samples were then studied the structural, optical, and magnetic properties. The structural analyses basing on x-ray diffraction and transmission electron microscope revealed the absence of Mn-related secondary phases. The study of photoluminesce ... [J. Appl. Phys. 108, 044910 (2010)] published Tue Aug 24, 2010.
Local intermixing on Ge/Si heterostructures at low temperature growth
H. H. Cheng, W. P. Huang, V. I. Mashanov, and G. Sun
We report experimental investigation on a series of strained Ge/Si heterostructure with various Ge thicknesses (the order of nanometers) grown at low temperatures (260 degrees C). In addition to the conventional uniform intermixing at the Ge/Si interface for structures with thin Ge layer, local int ... [J. Appl. Phys. 108, 044314 (2010)] published Tue Aug 24, 2010.
Indium-doped ZnO nanowires: Optical properties and room-temperature ferromagnetism
K. W. Liu, M. Sakurai, and M. Aono
We report the optical and magnetic properties of ZnO, ZnInO, and ZnInO nanowires (NWs). All samples have similar wirelike shape with an average diameter of about 70 nm and a length of about 10 [mu]m. The comparison of photoluminescence (PL) spectra at 10 K indicated that a new broad emission band a ... [J. Appl. Phys. 108, 043516 (2010)] published Mon Aug 23, 2010.
The measured dependence of the lateral ambipolar diffusion length on carrier injection-level in Stranski-Krastanov quantum dot devices
D. Naidu, P. M. Smowton, and H. D. Summers
Using the segmented contact method we separate and numerically evaluate the components making up the threshold current density dependence of quantum dot ridge waveguide lasers. An increasing internal optical mode loss and an increasing lateral out-diffusion current are the significant processes in r ... [J. Appl. Phys. 108, 043108 (2010)] published Thu Aug 26, 2010.
Multiphoton-absorption induced ultraviolet luminescence of ZnO nanorods using low-energy femtosecond pulses
Susanta Kumar Das, Mahua Biswas, Daragh Byrne, Martin Bock, Enda McGlynn et al.
Multiphoton-absorption (MPA) induced ultraviolet (UV) luminescence of ZnO nanorods grown by vapor phase transport was demonstrated using ultrafast excitation at pulse energies in the few nanojoules range, directly generated by a Ti:sapphire laser oscillator at wavelengths around 800 nm. The dependen ... [J. Appl. Phys. 108, 043107 (2010)] published Wed Aug 25, 2010.
Photoluminescence spectroscopy and lifetime measurements from self-assembled semiconductor-metal nanoparticle hybrid arrays
M. Haridas, J. K. Basu, D. J. Gosztola, and G. P. Wiederrecht
We present results of photoluminescence spectroscopy and lifetime measurements on thin film hybrid arrays of semiconductor quantum dots and metal nanoparticles embedded in a block copolymer template. The intensity of emission as well as the measured lifetime would be controlled by varying the volume ... [Appl. Phys. Lett. 97, 083307 (2010)] published Thu Aug 26, 2010.
Tuning single GaAs quantum dots in resonance with a rubidium vapor
N. Akopian, U. Perinetti, L. Wang, A. Rastelli, O. G. Schmidt et al.
We study single GaAs quantum dots with optical transitions that can be brought into resonance with the widely used D transitions of rubidium atoms. We achieve resonance by Zeeman or Stark shifting the quantum dot levels. We discuss an energy stabilization scheme based on the absorption of quantum do ... [Appl. Phys. Lett. 97, 082103 (2010)] published Mon Aug 23, 2010.
Optical spectroscopy of cubic GaN in nanowires
J. Renard, G. Tourbot, D. Sam-Giao, C. Bougerol, B. Daudin et al.
We show that highly homogeneous cubic GaN can be grown by plasma-assisted molecular beam epitaxy on wurtzite GaN nanowires. The line width of the donor bound exciton is below 3 meV and can reach 1.6 meV in the best parts of the studied sample. This allows to perform a detailed spectroscopy of cubic ... [Appl. Phys. Lett. 97, 081910 (2010)] published Thu Aug 26, 2010.
Optically Generated 2-Dimensional Photonic Cluster State from Coupled Quantum Dots
Sophia E. Economou, Netanel Lindner, and Terry Rudolph
We propose a method to generate a two-dimensional cluster state of polarization encoded photonic qubits from two coupled quantum dot emitters. We combine the proposal for generating one-dimensional cluster state strings from a single dot, with a new proposal for an induced conditional phase gate bet ... [Phys. Rev. Lett. 105, 093601 ] published .
A critical factor affecting on the performance of blue-violet InGaN multiquantum well laser diodes: Nonradiative centers
D. M. Shin, J. Park, D. H. Nguyen, Y. D. Jang, K. J. Yee et al.
Carrier lifetime at room temperature (RT) was measured for blue-violet emitting InGaN multiquantum wells as a function of excitation intensity. The carrier lifetime of a p/n-doped waveguide sample (PNLD) was longer than those of undoped or n-doped waveguide samples. For PNLD, the long decay componen ... [Appl. Phys. Lett. 97, 071910 (2010)] published Fri Aug 20, 2010.
A fine-focusing x-ray source using carbon-nanofiber field emitter
W. Sugimoto, S. Sugita, Y. Sakai, H. Goto, Y. Watanabe et al.
A fine-focusing x-ray source has been constructed employing a field electron emitter prepared by growing carbon-nanofibers (CNFs) on a metal tip. The x-ray source is composed of a CNF field electron emitter, an electrostatic lens, two magnetic lenses, and a W-target for generating x-rays by electron ... [J. Appl. Phys. 108, 044507 (2010)] published Thu Aug 26, 2010.
A versatile high resolution scanning tunneling potentiometry implementation
T. Druga, M. Wenderoth, J. Homoth, M. A. Schneider, and R. G. Ulbrich
We have developed a new scanning tunneling potentiometry technique which canwith only minor changes of the electronic setupbe easily added to any standard scanning tunneling microscope (STM). This extension can be combined with common STM techniques such as constant current imaging or scanning tunne ... [Rev. Sci. Instrum. 81, 083704 (2010)] published Thu Aug 26, 2010.
Image force microscopy of molecular resonance: A microscope principle
I. Rajapaksa, K. Uenal, and H. Kumar Wickramasinghe
We demonstrate a technique in microscopy which extends the domain of atomic force microscopy to optical spectroscopy at the nanometer scale. We show that molecular resonance of feature sizes down to the single molecular level can be detected and imaged purely by mechanical detection of the force gra ... [Appl. Phys. Lett. 97, 073121 (2010)] published Fri Aug 20, 2010.
Imaging Pauli Repulsion in Scanning Tunneling Microscopy
C. Weiss, C. Wagner, C. Kleimann, M. Rohlfing, F. S. Tautz et al.
A scanning tunneling microscope (STM) has been equipped with a nanoscale force sensor and signal transducer composed of a single D molecule that is confined in the STM junction. The uncalibrated sensor is used to obtain ultrahigh geometric image resolution of a complex organic molecule adsorbed on a ... [Phys. Rev. Lett. 105, 086103 ] published .
Reversible electric control of exchange bias in a multiferroic field-effect device
S. M. Wu, Shane A. Cybart, P. Yu, M. D. Rossell, J. X. Zhang et al.
Electric-field control of magnetization has many potential applications in magnetic memory storage, sensors and spintronics. One approach to obtain this control is through multiferroic materials. Instead of using direct coupling between ferroelectric and ferromagnetic order parameters in a single-ph ... [Nature Mater. 9, 756 (2010)] published Wed Aug 25, 2010.
A perpendicular-anisotropy CoFeBMgO magnetic tunnel junction
S. Ikeda, K. Miura, H. Yamamoto, K. Mizunuma, H. D. Gan et al.
Magnetic tunnel junctions (MTJs) with ferromagnetic electrodes possessing a perpendicular magnetic easy axis are of great interest as they have a potential for realizing next-generation high-density non-volatile memory and logic chips with high thermal stability and low critical current for current ... [Nature Mater. 9, 721 (2010)] published Wed Aug 25, 2010.
Optical Probing of the Spin Polarization of the nu=5/2 Quantum Hall State
M. Stern, P. Plochocka, V. Umansky, D. K. Maude, M. Potemski et al.
We apply polarization resolved photoluminescence spectroscopy to measure the spin polarization of a two dimensional electron gas in perpendicular magnetic field. We find that the splitting between the sigma and sigma polarizations exhibits a sharp drop at nu=5/2 and is equal to the bare Zeeman energ ... [Phys. Rev. Lett. 105, 096801 ] published .
Vortex nucleation in spin-torque nanocontact oscillators
T. Devolder, Joo-Von Kim, M. Manfrini, W. van Roy, L. Lagae et al.
We present an experimental study of the nucleation rate associated with current-driven vortex oscillations in magnetic nanocontacts. We find that the nucleation and subsequent steady-state oscillation of a vortex can be initiated using current pulses as short as a few nanoseconds, yielding instant o ... [Appl. Phys. Lett. 97, 072512 (2010)] published Fri Aug 20, 2010.
Spin and electronic correlations in gated graphene quantum rings
P. Potasz, A. D. Guclu, and P. Hawrylak
We present a theory of graphene quantum rings designed to produce degenerate shells of single-particle states close to the Fermi level. We show that populating these shells with carriers using a gate leads to correlated ground states with finite total electronic spin. Using a combination of tight-bi ... [Phys. Rev. B 82, 075425 ] published .
Band structure scenario for the giant spin-orbit splitting observed at the Bi/Si(111) interface
Emmanouil Frantzeskakis, Stephane Pons, and Marco Grioni
The Bi/Si(111) (sqrt(3) x sqrt(3))R30 degrees trimer phase offers a prime example of a giant spin-orbit splitting of the electronic states at the interface with a semiconducting substrate. We have performed a detailed angle-resolved photoemission spectroscopy (ARPES) study to clarify the complex to ... [Phys. Rev. B 82, 085440 ] published .
Fast Advection of Magnetic Fields by Hot Electrons
L. Willingale, A. G. R. Thomas, P. M. Nilson, M. C. Kaluza, S. Bandyopadhyay et al.
Experiments where a laser-generated proton beam is used to probe the megagauss strength self-generated magnetic fields from a nanosecond laser interaction with an aluminum target are presented. At intensities of 10 W cm and under conditions of significant fast electron production and strong heat fl ... [Phys. Rev. Lett. 105, 095001 ] published .
Intervalley plasmons in graphene
T. Tudorovskiy and S. A. Mikhailov
The spectrum of two-dimensional (2D) plasma waves in graphene has been recently studied in the Dirac fermion model. We take into account the whole dispersion relation for graphene electrons in the tight-binding approximation and the local-field effects in the electrodynamic response. Near the wave v ... [Phys. Rev. B 82, 073411 ] published .
Electron-electron interactions in the conductivity of graphene
A. A. Kozikov, A. K. Savchenko, B. N. Narozhny, and A. V. Shytov
The effect of electron-electron interaction on the low-temperature conductivity of graphene is investigated experimentally. Unlike in other two-dimensional systems, the electron-electron interaction correction in graphene is sensitive to the details of disorder. A temperature regime of the interacti ... [Phys. Rev. B 82, 075424 ] published .
Tunable Fano-Kondo resonance in side-coupled double quantum dot systems
Chung-Hou Chung and Tsung-Han Lee
We study the interference between the Fano and Kondo effects in a side-coupled double quantum dot system where one of the quantum dots couples to conduction-electron bath while the other dot only side couples to the first dot via antiferromagnetic (AF) spin-exchange coupling. We apply both the pertu ... [Phys. Rev. B 82, 085325 ] published .
Temperature dependence of the diffusive conductivity of bilayer graphene
Shaffique Adam and M. D. Stiles
Assuming diffusive carrier transport and employing an effective medium theory, we calculate the temperature dependence of bilayer graphene conductivity due to Fermi-surface broadening as a function of carrier density. We find that the temperature dependence of the conductivity depends strongly on th ... [Phys. Rev. B 82, 075423 ] published .
Bolometric terahertz detection in pinched-off quantum point contacts
J. W. Song, G. R. Aizin, J. Mikalopas, Y. Kawano (河野行雄), K. Ishibashi (石橋幸治) et al.
Terahertz (>1 THz) irradiation of pinched-off quantum point contacts (QPCs) generates a pronounced photo-current due to radiation-induced heating. This response is reproduced by a model of temperature-dependent transmission through a saddle potential, confirming its bolometric nature. ... [Appl. Phys. Lett. 97, 083109 (2010)] published Thu Aug 26, 2010.
Coherent measurements of high-order electronic correlations in quantum wells
Daniel B. Turner and Keith A. Nelson
Strong, long-range Coulomb interactions can lead to correlated motions of multiple charged particles, which can induce important many-body effects in semiconductors. The exciton states formed from correlated electronhole pairs have been studied extensively, but basic properties of multiple-exciton ... [Nature 466, 1089 (2010)] published Fri Aug 27, 2010.
Impurity-assisted nanoscale localization of plasmonic excitations in graphene
Rodrigo A. Muniz, Hari P. Dahal, A. V. Balatsky, and Stephan Haas
A nonlocal quantum-mechanical model is employed to compute plasmonic excitations of graphene in the presence of an impurity potential. A full diagonalization of the polarization operator is performed, allowing the extraction of all its poles. It is demonstrated that impurities induce the formation o ... [Phys. Rev. B 82, 081411 ] published .
Two-dimensional carbon semiconductor: Density functional theory calculations
David J. Appelhans, Zhibin Lin, and Mark T. Lusk
We show that patterned defects can be used to disrupt the sublattice symmetry of graphene so as to open up a band gap. This way of modifying graphene's electronic structure does not rely on external agencies, the addition of new elements or special boundaries. The method is used to predict a planar, ... [Phys. Rev. B 82, 073410 ] published .
Dutta et al. Reply:
A. Dutta, M. Bhattacharya, P. Barat, P. Mukherjee, N. Gayathri et al.
A Reply to the Comment by Christopher R. Weinberger. ... [Phys. Rev. Lett. 105, 099602 ] published .
Comment on Lattice Resistance to Dislocation Motion at the Nanoscale
Christopher R. Weinberger
A Comment on the Letter by A. Dutta et al., Phys. Rev. Lett. 101, 115506 (2008). The authors of the Letter offer a Reply. ... [Phys. Rev. Lett. 105, 099601 ] published .
Rotation-dependent epitaxial relations between graphene and the Si-terminated SiC substrate
V. Sorkin and Y. W. Zhang
We study the rotation-dependent epitaxial relations between graphene nanoflake and the Si-terminated 4H-SiC(0001) substrate. Depending on the rotation angle between the nanoflake and substrate surface, we find that Si-C bonds formed between the C atoms in the nanoflake and Si atoms on the SiC surfac ... [Phys. Rev. B 82, 085434 ] published .
Size-Dependent Amorphization of Nanoscale YO at High Pressure
Lin Wang, Wenge Yang, Yang Ding, Yang Ren, Siguo Xiao et al.
YO with particle sizes ranging from 5 nm to 1 [mu]m were studied at high pressure using x-ray diffraction and Raman spectroscopy techniques. Nanometer-sized YO particles are shown to be more stable than their bulk counterparts, and a grain size-dependent crystalline-amorphous transition was discove ... [Phys. Rev. Lett. 105, 095701 ] published .
Graphene nanoribbons subjected to axial stress
M. Neek-Amal and F. M. Peeters
Atomistic simulations are used to study the bending of rectangular graphene nanoribbons subjected to axial stress both for free boundary and supported boundary conditions. The shapes of the deformations of the buckled graphene nanoribbons, for small values of the stress, are sine waves where the num ... [Phys. Rev. B 82, 085432 ] published .
Influence of surface energy anisotropy on the dynamics of quantum dot growth
Jean-Noel Aqua and Thomas Frisch
We investigate the influence of surface energy anisotropy on the dynamics of quantum dot growth by looking at the long-time dynamics of the morphological (Asaro-Tiller-Grinfeld) instability of a strained thin film driven by surface diffusion during growth and annealing. We derive a continuum model a ... [Phys. Rev. B 82, 085322 ] published .

Virtual Journal of Ultrafast Science

Virtual Journal of Ultrafast Science

High-harmonic gyrotron with sectioned cavity
I. V. Bandurkin, Yu. K. Kalynov, and A. V. Savilov
High-harmonic large-orbit gyrotrons require long-length operating cavities because of both a weak electron-wave coupling and relatively low electron currents. Since diffraction Q factors of such cavities are very high, a large fraction of the radiated power is dissipated in Ohmic losses. A sectioned ... [Phys. Plasmas 17, 073101 (2010)] published Thu Jul 8, 2010.
Ultralong-range energy transfer by interatomic Coulombic decay in an extreme quantum system
Nicolas Sisourat, Nikolai V. Kryzhevoi, Premysl KolorenC, Simona Scheit, Till Jahnke et al.
When an atom is electronically excited, it relaxes by emitting a photon or an electron. These carry essential information on the electronic structure of their emitter. However, if an atom is embedded in a chemical environment, another ultrafast non-radiative decay process called interatomic Coulomb ... [Nature Phys. 6, 508 (2010)] published Thu Jul 1, 2010.
Multiple-laser flash shadowgraphy system for terminal studies of small-caliber projectiles
R. C. Kalonia, Gautam Mitra, G. S. Singh, R. K. Varma, Manpreet Singh et al.
A multiple-laser flash shadowgraphy system has been innovatively designed and developed to study the terminal effects of projectiles. The system has been designed based on modulated laser diodes operated at low voltage and current. In order to study the ballistics effects of small arms, an exposure ... [Opt. Eng. 49, 064303 (2010)] published Thu Jul 1, 2010.
Laser-induced water condensation in air
Philipp Rohwetter, Jerome Kasparian, Kamil Stelmaszczyk, Zuoqiang Hao, Stefano Henin et al.
Triggering rain on demand is an old dream of mankind, with a huge potential socio-economical benefit. To date, efforts have mainly focused on cloud-seeding using silver salt particles. We demonstrate that self-guided ionized filaments generated by ultrashort laser pulses are also able to induce wate ... [Nat. Photonics 4, 451 (2010)] published Tue Jul 6, 2010.
Organic photonics for communications
Jenny Clark and Guglielmo Lanzani
Photons as information carriers have the potential to meet the ever-increasing demands on bandwidth and information density in fields such as information and communication technology, biomedicine and computing. Organic semiconductors may be well-suited to such applications, thanks to their ability t ... [Nat. Photonics 4, 438 (2010)] published Tue Jul 6, 2010.
Embellishment of microfluidic devices via femtosecond laser micronanofabrication for chip functionalization
Juan Wang, Yan He, Hong Xia, Li-Gang Niu, Ran Zhang et al.
This paper demonstrates the embellishment of existing microfluidic devices with integrated three dimensional (3D) micronanostructures via femtosecond laser micronanofabrication, which, for the first time, proves two-photon photopolymerization (TPP) to be a powerful technology for chip functionalizat ... [Lab Chip 10, 1993 (2010)] published Thu Jul 15, 2010.
Efficient laser-ion acceleration from closely stacked ultrathin foils
T. Kluge, W. Enghardt, S. D. Kraft, U. Schramm, Y. Sentoku et al.
A new scheme to efficiently accelerate protons by a single linear polarized high-intensity ultrashort laser pulse using multiple ultrathin foils is proposed. The foils are stacked at a spacing comparable to their thickness and subsequently irradiated by the same laser pulse. The foil thicknesses are ... [Phys. Rev. E 82, 016405 ] published .
Proton radiography of a shock-compressed target
A. Ravasio, L. Romagnani, S. Le Pape, A. Benuzzi-Mounaix, C. Cecchetti et al.
In this paper we report on the radiography of a shock-compressed target using laser produced proton beams. A low-density carbon foam target was shock compressed by long pulse high-energy laser beams. The shock front was transversally probed with a proton beam produced in the interaction of a high in ... [Phys. Rev. E 82, 016407 ] published .
Direct particle acceleration by two identical crossed radially polarized laser beams
Yousef I. Salamin
Electrons and alpha particles injected midway between two ultrahigh intensity crossed laser beams of radial polarization are shown to be accelerated in vacuum to several gigaelectron volts and to have average energy gradients in excess of 150 GeV/m. A unique model of the crossing beams is suggested, ... [Phys. Rev. A 82, 013823 ] published .
Spectral tunneling of lattice nonlocal solitons
Yaroslav V. Kartashov, Victor A. Vysloukh, and Lluis Torner
We address spectral tunneling of walking spatial solitons in photorefractive media with nonlocal diffusion component of the nonlinear response and an imprinted shallow optical lattice. In contrast to materials with local nonlinearities, where solitons traveling across the lattice close to the Bragg ... [Phys. Rev. A 82, 013806 ] published .
Radiation generated by bunched electron beams in corrugated plasma channels
Thomas M. Antonsen, Jr.
The excitation of radiation by bunched electron beams propagating in miniature corrugated plasma channels is considered. It is shown that the rate at which power is radiated by a beam is characterized by impedance that depends on the properties of the channel. For experimentally obtainable parameter ... [Phys. Plasmas 17, 073112 (2010)] published Fri Jul 30, 2010.
A computational study of x-ray emission from laser-irradiated Ge-doped foams
Jeffrey D. Colvin, Kevin B. Fournier, Mark J. May, and Howard A. Scott
New advances in fabrication of low-density high-Z-doped foams have opened new windows on understanding how materials that are not in local thermodynamic equilibrium (LTE) are heated and radiate. Simulations are discussed in this paper of the x-ray spectral emissions from laser-irradiated very low-de ... [Phys. Plasmas 17, 073111 (2010)] published Thu Jul 29, 2010.
Correlation between laser accelerated MeV proton and electron beams using simple fluid model for target normal sheath acceleration
M. Tampo, S. Awano, P. R. Bolton, K. Kondo, K. Mima et al.
High density energetic electrons that are created by intense laser plasma interactions drive MeV proton acceleration. The correlation between accelerated MeV protons and escaped electrons is experimentally investigated at laser intensities in the range of 1010 W/cm with S-polarization. Observed pro ... [Phys. Plasmas 17, 073110 (2010)] published Thu Jul 29, 2010.
Quasitransient backward Raman amplification of powerful laser pulses in dense plasmas with multicharged ions
V. M. Malkin and N. J. Fisch
The range of plasma parameters, where the efficient quasitransient backward Raman amplification (QBRA) of powerful laser pulses is possible, is determined for dense plasmas with multicharged ions. Approximate scalings that portray in a simple way the efficient QBRA range in multidimensional paramete ... [Phys. Plasmas 17, 073109 (2010)] published Tue Jul 27, 2010.
Ionization heating in rare-gas clusters under intense XUV laser pulses
Mathias Arbeiter and Thomas Fennel
The interaction of intense extreme ultraviolet (XUV) laser pulses (lambda=32 nm, I=1010 W/cm) with small rare-gas clusters (Ar) is studied by quasiclassical molecular dynamics simulations. Our analysis supports a very general picture of the charging and heating dynamics in finite samples under shor ... [Phys. Rev. A 82, 013201 ] published .
Modulated vortex solitons of four-wave mixing
Yanpeng Zhang, Zhiqiang Nie, Yan Zhao, Changbiao Li, Ruimin Wang et al.
We experimentally demonstrate the vortex solitons of four-wave mixing (FWM) in multi-level atomic media created by the interference patterns with superposing three or more waves. The modulation effect of the vortex solitons is induced by the cross-Kerr nonlinear dispersion due to atomic coherence in ... [Opt. Express 18, 10963 (2010)] published Wed Jul 7, 2010.
Effect of self-generated magnetic fields on fast-electron beam divergence in solid targets
X Yuan, A Robinson, M Quinn, D Carroll, M Borghesi et al.
The collimating effect of self-generated magnetic fields on fast-electron transport in solid aluminium targets irradiated by ultra-intense, picosecond laser pulses is investigated in this study. As the target thickness is varied in the range of 25 [mu]m to 1.4 mm, the maximum energies of protons acc ... [New J. Phys. 12, 063018 (2010)] published Thu Jul 1, 2010.
Femtosecond electronic response of atoms to ultra-intense X-rays
L. Young, E. P. Kanter, B. Krssig, Y. Li, A. M. March et al.
An era of exploring the interactions of high-intensity, hard X-rays with matter has begun with the start-up of a hard-X-ray free-electron laser, the Linac Coherent Light Source (LCLS). Understanding how electrons in matter respond to ultra-intense X-ray radiation is essential for all applications. H ... [Nature 466, 56 (2010)] published Thu Jul 1, 2010.
Recombination effects during expansion into vacuum in laser produced Sn plasma
Russell A. Burdt, Yoshifumi Ueno, Yezheng Tao, Sam Yuspeh, Mark S. Tillack et al.
The distance over which the charge state distribution evolves during the expansion of laser produced Sn plasma in vacuum is investigated experimentally. This distance is found to be less than 6 cm with a planar target irradiated by a 1.064 [mu]m laser at 8.3 x 10 W/cm but greater than 60 cm when a ... [Appl. Phys. Lett. 97, 041502 (2010)] published Fri Jul 30, 2010.
Controlling the Pointing Angle of a Relativistic Electron Beam in a Weakly-Nonlinear Laser Wakefield Accelerator
Nasr A. M. Hafz, Tae Jun Yu, Seong Ku Lee, Tae Moon Jeong, Jae Hee Sung et al.
Advanced laser wakefield accelerators offer electron beams which could be useful for many applications. However, the problem of stabilizing the electron beam parameters has not been resolved yet. Here, we report the generation of a relativistic electron beam with a stabilized pointing angle of 2 mra ... [Appl. Phys. Express 3, 076401 (2010)] published Mon Jul 26, 2010.
A high resolution, broad energy acceptance spectrometer for laser wakefield acceleration experiments
Christopher M. S. Sears, Sofia Benavides Cuevas, Ulrich Schramm, Karl Schmid, Alexander Buck et al.
Laser wakefield experiments present a unique challenge in measuring the resulting electron energy properties due to the large energy range of interest, typically several 100 MeV, and the large electron beam divergence and pointing jitter >1 mrad. In many experiments the energy resolution and accura ... [Rev. Sci. Instrum. 81, 073304 (2010)] published Wed Jul 21, 2010.
Modeling of laser induced plasma expansion in the presence of non-Maxwellian electrons
D. Bennaceur-Doumaz and M. Djebli
The one-dimensional expansion into vacuum of ion-electron plasma produced by laser ablation is investigated. The ions considered as an ideal fluid are governed by a fluid model where charge quasineutrality is assumed to prevail, while electron density follows a non-Maxwellian distribution. Showing t ... [Phys. Plasmas 17, 074501 (2010)] published Thu Jul 8, 2010.
Ultraintense ion beams driven by a short-wavelength short-pulse laser
J. Badziak and S. Jablonski
The results of particle-in-cell simulations are reported which demonstrate that a short-wavelength (lambda<=0.5 [mu]m) short-pulse laser driver can produce much more intense ion beams than the commonly used long-wavelength (lambda~1 [mu]m) ones. In particular, such a driver allows for efficient ge ... [Phys. Plasmas 17, 073106 (2010)] published Thu Jul 22, 2010.
Relativistic Quasimonoenergetic Positron Jets from Intense Laser-Solid Interactions
Hui Chen, S. C. Wilks, D. D. Meyerhofer, J. Bonlie, C. D. Chen et al.
Detailed angle and energy resolved measurements of positrons ejected from the back of a gold target that was irradiated with an intense picosecond duration laser pulse reveal that the positrons are ejected in a collimated relativistic jet. The laser-positron energy conversion efficiency is ~2 x 10. ... [Phys. Rev. Lett. 105, 015003 ] published .
Observations of low-aberration plasma lens focusing of relativistic electron beams at the underdense threshold
M. C. Thompson, H. Badakov, J. B. Rosenzweig, G. Travish, N. Barov et al.
Focusing of a 15 MeV electron bunch by a plasma lens operated at the threshold of the underdense regime has been demonstrated. The strong, 1.7 cm focal length, plasma lens focused both transverse directions simultaneously and reduced the minimum area of the beam spot by a factor of 23. It is shown t ... [Phys. Plasmas 17, 073105 (2010)] published Wed Jul 21, 2010.
Quantum electrodynamics vacuum polarization modification of photon acceleration in plasma
Zhigang Bu and Peiyong Ji
The modification of photon frequency shifting based on taking into account the nonlinear quantum electrodynamics vacuum properties in plasma is studied. Motion equations of a laser field propagating in a plasma are derived from the HeisenbergEuler Lagrangian density. It is found that besides the cla ... [Phys. Plasmas 17, 073103 (2010)] published Fri Jul 16, 2010.
Photon acceleration in the amplified plasma density wake of two copropagating laser pulses
G. Raj, M. R. Islam, B. Ersfeld, and D. A. Jaroszynski
Photon acceleration of a laser pulse occurs in a medium with a space and time-varying permittivity. Using Hamiltonian formulation, a theoretical study of the frequency upshift of a probe laser pulse, which is considered as a quasiphoton or test particle, propagating through an amplified plasma densi ... [Phys. Plasmas 17, 073102 (2010)] published Wed Jul 14, 2010.
Classification and stability of plasma motion in periodic linearly polarized relativistic waves
G. Lehmann and K. H. Spatschek
Based on a relativistic fluid-Maxwell model, laser-induced plasma dynamics is investigated for relativistic periodic waves. Within a one-dimensional (1D) description, the AkhiezerPolovin model is applied to the existence of periodic, nonlinearly coupled electromagnetic and electrostatic waves, and t ... [Phys. Plasmas 17, 072102 (2010)] published Thu Jul 8, 2010.
Stimulated Raman Side Scattering in Laser Wakefield Acceleration
T. Matsuoka, C. McGuffey, P. G. Cummings, Y. Horovitz, F. Dollar et al.
Stimulated Raman side scattering of an ultrashort high power laser pulse is studied in experiments on laser wakefield acceleration. Experiments and simulations reveal that stimulated Raman side scattering occurs at the beginning of the interaction, that it contributes to the evolution of the pulse p ... [Phys. Rev. Lett. 105, 034801 ] published .
Light Bullets by Synthetic Diffraction-Dispersion Matching
Valery E. Lobanov, Yaroslav V. Kartashov, and Lluis Torner
We put forward a new approach to generate stable, fully three-dimensional light bullets, which is based on the matching of the intrinsic material dispersion with a suitable effective diffraction. The matching is achieved in adequate waveguide arrays whose refractive index is periodically modulated a ... [Phys. Rev. Lett. 105, 033901 ] published .
Hot Electrons Transverse Refluxing in Ultraintense Laser-Solid Interactions
S. Buffechoux, J. Psikal, M. Nakatsutsumi, L. Romagnani, A. Andreev et al.
We have analyzed the coupling of ultraintense lasers (at ~2 x 10 W/cm) with solid foils of limited transverse extent (~10 s of [mu]m) by monitoring the electrons and ions emitted from the target. We observe that reducing the target surface area allows electrons at the target surface to be reflecte ... [Phys. Rev. Lett. 105, 015005 ] published .
Spatiotemporal evolution of high-power relativistic laser pulses in electron-positron-ion plasmas
A. Sharma, I. Kourakis, and P. K. Shukla
The spatiotemporal pulse dynamics of a high-power relativistic laser pulse interacting with an electron-positron-ion plasmas is investigated theoretically and numerically. The occurrence of pulse compression is studied. The dependence of the mechanism on the concentration of the background ions in e ... [Phys. Rev. E 82, 016402 ] published .
Near-critical phase explosion promoting breakdown plasma ignition during laser ablation of graphite
A. A. Ionin, S. I. Kudryashov, and L. V. Seleznev
Removal rate, air shock, and ablative recoil pressure parameters were measured as a function of laser intensity I during nanosecond laser ablation of graphite. Surface vaporization of molten graphite at low intensities I<0.15 GW/cm was observed to transform into its near-critical phase explosion (i ... [Phys. Rev. E 82, 016404 ] published .
Heating dynamics and extreme ultraviolet radiation emission of laser-produced Sn plasmas
S. Yuspeh, K. L. Sequoia, Y. Tao, M. S. Tillack, R. A. Burdt et al.
The impact of 1.064 [mu]m laser absorption depth on the heating and in-band (2% bandwidth) 13.5 nm extreme ultraviolet emissions in Sn plasmas is investigated experimentally and numerically. In-band emission lasting longer than the laser pulse and separation between the laser absorption and in-band ... [Appl. Phys. Lett. 96, 261501 (2010)] published Wed Jun 30, 2010.
Optical Realization of Relativistic Non-Hermitian Quantum Mechanics
Stefano Longhi
Light propagation in distributed-feedback optical structures with gain or loss regions is shown to provide an accessible laboratory tool to visualize in optics the spectral properties of the one-dimensional Dirac equation with non-Hermitian interactions. Spectral singularities and [script P][script ... [Phys. Rev. Lett. 105, 013903 ] published .
Time-Domain Coherent Anti-Stokes Raman Scattering Signal Detection for Terahertz Vibrational Spectroscopy Using Chirped Femtosecond Pulses
Masahiko Tani, Toshiyuki Koizumi, Hisashi Sumikura, Mariko Yamaguchi, Kohji Yamamoto et al.
A new scheme for low-frequency coherent anti-Stokes Raman scattering spectroscopy (CARS) using chirped femtosecond pulses is proposed and demonstrated. Two chirped broadband optical pulses created terahertz (THz) polarization in the sample and generated CARS signal. The chirped CARS signal was then ... [Appl. Phys. Express 3, 072401 (2010)] published Mon Jul 26, 2010.
High harmonic emission from a superposition of multiple unrelated frequency fields
T. Siegel, R. Torres, D. J. Hoffmann, L. Brugnera, I. Procino et al.
We report observations and analysis of high harmonic generation driven by a superposition of fields at 1290 nm and 780 nm. These fields are not commensurate in frequency and the superposition leads to an increase in the yield of the mid-plateau harmonics of more than two orders of magnitude compared ... [Opt. Express 18, 6853 (2010)] published Wed Jul 7, 2010.
Analytical description of gain depletion and recovery in quantum dot optical amplifiers
Ermin Malic, Marten Richter, Gregor Hartmann, Jordi Gomis-Bresco, Ulrike Woggon et al.
We present an analytical description of ultrashort femtosecond pumpprobe experiments and investigate the gain response of quantum dot (QD) semiconductor optical amplifiers. The calculation provides a full analytical solution of numerical studies to recent experiments in such structures (Gomis-Bresco ... [New J. Phys. 12, 063012 (2010)] published Thu Jul 1, 2010.
Ultra-fast responding and recovering CHOH sensors using SnO hollow spheres prepared and activated by Ni templates
Hae-Ryong Kim, Kwon-Il Choi, Kang-Min Kim, Il-Doo Kim, Guozhong Cao et al.
Ultra-fast responding and recovering CHOH sensors were prepared using nanoscale SnO hollow spheres with NiO-functionalized inner walls. The exceptional ultra-fast recovery characteristics were attributed to the catalytic surface reaction assisted by NiO at the inner shell. ... [Chem. Commun. 46, 5061 (2010)] published Tue Jul 6, 2010.
Bright vector solitons in cross-defocusing nonlinear media
A. I. Yakimenko, O. O. Prikhodko, and S. I. Vilchynskyi
We study two-dimensional soliton-soliton vector pairs in media with self-focusing nonlinearities and defocusing cross interactions. The general properties of the stationary states and their stability are investigated. The different scenarios of instability are observed using numerical simulations. T ... [Phys. Rev. E 82, 016605 ] published .
Erratum: Infrared Two-Color Multicycle Laser Field Synthesis for Generating an Intense Attosecond Pulse [Phys. Rev. Lett. 104, 233901 (2010)]
Eiji J. Takahashi, Pengfei Lan, Oliver D. Mucke, Yasuo Nabekawa, and Katsumi Midorikawa
Abstract not available. [Phys. Rev. Lett. 105, 049902 ] published .
Distortionless large-ratio stretcher for ultra-short pulses using photonic crystal fiber
L.-G. Li, L.-S. Yan, G.-Y. Feng, W. Pan, B. Luo et al.
A large-ratio stretcher for ultra-short pulses is proposed based on photonic crystal fiber (PCF). Through proper design of the PCF structure, we obtain over 300-nm wavelength range with flattened dispersion characteristics. Analysis indicates that 1-km of such fiber can broaden over 10,000 times for ... [Opt. Express 18, 12341 (2010)] published Wed Jul 7, 2010.
Fabrication of three-dimensional 1 x 4 splitter waveguides inside a glass substrate with spatially phase modulated laser beam
Masaaki Sakakura, Tsutomu Sawano, Yasuhiko Shimotsuma, Kiyotaka Miura, and Kazuyuki Hirao
Multiple light spots can be generated by modulating the spatial phase distribution of laser beam with a spatial light modulator (SLM). In this paper, we demonstrate the fabrication of three-dimensional 1 x 4 splitter waveguides inside a glass by focusing multiple light spots of femtosecond (fs) la ... [Opt. Express 18, 12136 (2010)] published Wed Jul 7, 2010.
Wideband spectral compression of wavelength-tunable ultrashort soliton pulse using comb-profile fiber
N. Nishizawa, K. Takahashi, Y. Ozeki, and K. Itoh
We demonstrated spectral compression of ultrashort soliton pulses in a wide wavelength region based on an adiabatic soliton spectral compression technique using a comb-profile fiber. The comb-profile fiber was carefully designed using numerical analysis and fabricated using a conventional single-mod ... [Opt. Express 18, 11700 (2010)] published Wed Jul 7, 2010.
Relativistic Single-Cycled Short-Wavelength Laser Pulse Compressed from a Chirped Pulse Induced by Laser-Foil Interaction
L. L. Ji (吉亮亮), B. F. Shen (沈百飞), D. X. Li (李冬雪), D. Wang (王丁), Y. X. Leng (冷雨欣) et al.
By particle-in-cell simulation and analysis, we propose a plasma approach to generate a relativistic chirped pulse based on a laser-foil interaction. When two counterpropagating circularly polarized pulses interact with an overdense foil, the driving pulse (with a larger laser field amplitude) will ... [Phys. Rev. Lett. 105, 025001 ] published .
Ultrafast optical imaging of the spin Hall effect of light in semiconductors
Jean-Michel Menard, Adam E. Mattacchione, Henry M. van Driel, Christine Hautmann, and Markus Betz
We experimentally demonstrate a general optical pump-probe technique to observe the spin Hall effect of light (SHEL) in an absorbing medium. In essence, a locally confined pump-induced modification of a material's absorptivity can effectively be used as an induced aperture allowing one to detect the ... [Phys. Rev. B 82, 045303 ] published .
Focal dynamics of multiple filaments: Microscopic imaging and reconstruction
P. Prem Kiran, Suman Bagchi, Siva Rama Krishnan, C. L. Arnold, G. Ravindra Kumar et al.
We observe the complete dynamics of the propagation of very intense, femtosecond laser pulses in air under tight focusing conditions via direct imaging of the entire interaction zone. The whole life history of the focused pulses is then reconstructed by means of numerical simulations. We show that b ... [Phys. Rev. A 82, 013805 ] published .
Collinear generation of ?ultrashort UV and XUV pulses
E. M. Bothschafter, A. Schiffrin, V. S. Yakovlev, A. M. Azzeer, F. Krausz et al.
We demonstrate the collinear generation of few-femtosecond ultraviolet and attosecond extreme ultraviolet pulses via a combination of third-harmonic and high harmonic generation in noble gases. The ultrashort coherent light bursts are produced by focusing a sub-1.5-cycle near-infrared/visible laser ... [Opt. Express 18, 9173 (2010)] published Wed Jul 7, 2010.
Infrared laser induced lateral photovoltaic effect observed in CuO nanoscale film
Liang Du and Hui Wang
The large infrared lateral photovoltaic effect (LPE) based on semiconductor structures has been a challenge for a long time because the light in this region is hard to be absorbed. In this study, we report an unusual infrared laser induced LPE observed in sputtered CuO thin films. The maximum open-c ... [Opt. Express 18, 9113 (2010)] published Wed Jul 7, 2010.
High accuracy polarization measurements using binary polarization rotators
X. Steve Yao, Xiaojun Chen, and Tiegen Liu
We report a novel system for the accurate measurement of all polarization related parameters, including polarization mode dispersion and polarization dependent loss, using binary magneto-optic polarization rotators. By taking advantage of the binary nature of the rotators, we achieved unprecedented ... [Opt. Express 18, 6667 (2010)] published Wed Jul 7, 2010.
Modal effects on pump-pulse propagation in an Ar-filled capillary
Richard T. Chapman, Thomas J. Butcher, Peter Horak, Francesco Poletti, Jeremy G. Frey et al.
Accurate three-dimensional modelling of nonlinear pulse propagation within a gas-filled capillary is essential for understanding and improving the XUV yield in high harmonic generation. We introduce both a new model based on a multimode generalized nonlinear Schrodinger equation and a novel spatio-s ... [Opt. Express 18, 13279 (2010)] published Wed Jul 7, 2010.
Formation of filament and plasma channel by the Bessel incident beam in Ar gas: role of the outer part of the beam
Zhenming Song and Takashi Nakajima
We theoretically investigate the formation of filament and plasma channel in Ar gas by intense femtosecond pulses in the Bessel, truncated Bessel, and combination of two Gaussian modes. Through the numerical results obtained by solving the generalized nonlinear Schrodinger equation coupled with the ... [Opt. Express 18, 12923 (2010)] published Wed Jul 7, 2010.
Measurements of nonlinear refractive index in scattering media
Prathyush Samineni, Zachary Perret, Warren S. Warren, and Martin C. Fischer
We have recently developed a spectral re-shaping technique to simultaneously measure nonlinear refractive index and nonlinear absorption. In this technique, the information about the nonlinearities is encoded in the frequency domain, rather than in the spatial domain as in the conventional Z-scan me ... [Opt. Express 18, 12727 (2010)] published Wed Jul 7, 2010.
Soliton mediated optical quantization in the transmission of one-dimensional photonic crystals
Falk Eilenberger, C. Martijn de Sterke, and Benjamin J. Eggleton
We report the experimental and numerical observation of step-like behavior of the high-intensity transmission deep inside the bandgap of a 1D photonic crystal. We show this to be a novel manifestation of the quantization of the soliton area, and derive an upper limit for the energy of the transmissi ... [Opt. Express 18, 12708 (2010)] published Wed Jul 7, 2010.
Hybrid metamaterial design and fabrication for terahertz resonance response enhancement
C. S. Lim, M. H. Hong, Z. C. Chen, N. R. Han, B. Luk'yanchuk et al.
Planar hybrid metamaterial with different split ring resonators (SRR) structure dimensions are fabricated on silicon substrates by femtosecond (fs) laser micro-lens array (MLA) lithography and lift-off process. The fabricated metamaterial structures consist of: (a) uniform metamaterial with 4 SRRs a ... [Opt. Express 18, 12421 (2010)] published Wed Jul 7, 2010.
Fourier domain pump-probe optical coherence tomography imaging of Melanin
Desmond Jacob, Ryan L. Shelton, and Brian E. Applegate
We report the development of a two-color Fourier domain Pump-Probe Optical Coherence Tomography (PPOCT) system. Tissue phantom experiments to characterize the system performance demonstrated imaging depths in excess of 725 [mu]m, nearly comparable to the base Optical Coherence Tomography system. PPO ... [Opt. Express 18, 12399 (2010)] published Wed Jul 7, 2010.
Simultaneous demodulation and demultiplexing of multi-rate WDM DPSK signals using a programmable wavelength-selective switch
Pegah Seddighian, Victor Torres-Company, and Lawrence R. Chen
We show demodulation and demultiplexing of multi-channel WDM differential phase-shift-keying (DPSK) signals operating simultaneously at 10 Gb/s and 40 Gb/s using a 1 x 4 wavelength selective switch. We achieve error-free performance for four channels equally spaced by 100 GHz propagated over an 85 k ... [Opt. Express 18, 11657 (2010)] published Wed Jul 7, 2010.
Ultrafast optical switching based on nonlinear polarization rotation in silicon waveguides
Jonathan Y. Lee, Lianghong Yin, Govind P. Agrawal, and Philippe M. Fauchet
We experimentally realize ultrafast all-optical switching in the 1.5-[mu]m spectral region using cross-phase modulation inside a 5-mm long silicon waveguide. Modulation depths of up to 90% and switching window durations ~1 ps are achieved using 500-fs pump pulses with energies below 10 pJ. ... [Opt. Express 18, 11514 (2010)] published Wed Jul 7, 2010.
Vibrational sum frequency generation spectroscopy using inverted visible pulses
Champika Weeraman, Steven A. Mitchell, Rune Lausten, Linda J. Johnston, and Albert Stolow
We present a broadband vibrational sum frequency generation (BB-VSFG) scheme using a novel ps visible pulse shape. We generate the fs IR pulse via standard procedures and simultaneously generate an `inverted' time-asymmetric narrowband ps visible pulse via second harmonic generation in the pump depl ... [Opt. Express 18, 11483 (2010)] published Wed Jul 7, 2010.
Mid-infrared modulated polarization gating for ultra-broadband supercontinuum generation
Weiyi Hong, Pengfei Wei, Qingbin Zhang, Shaoyi Wang, and Peixiang Lu
We propose a method to control the harmonic process by a mid-IR modulated polarization gating for the effective generation of an ultra-broadband supercontinuum in the neutral rare-gas media. Using a mid-IR polarization gating pulse modulated by a weaker 800-nm linearly polarized pulse, the ionizatio ... [Opt. Express 18, 11308 (2010)] published Wed Jul 7, 2010.
Passive mode-locked lasing by injecting a carbon nanotube-solution in the core of an optical fiber
Amos Martinez, Kaiming Zhou, Ian Bennion, and Shinji Yamashita
In this paper, we propose a saturable absorber (SA) device consisting on an in-fiber micro-slot inscribed by femtosecond laser micro fabrication, filled by a dispersion of Carbon Nanotubes (CNT). Due to the flexibility of the fabrication method, efficient and simple integration of the mode-locking d ... [Opt. Express 18, 11008 (2010)] published Wed Jul 7, 2010.
Defect solitons in two-dimensional optical lattices
W. H. Chen, X. Zhu, T. W. Wu, and R. H. Li
We report on the existence and stability of solitons in a defect embedded in a square optical lattice based on a photorefractive crystal with focusing saturable nonlinearity. These solitons exist in different bandgaps due to the change of defect intensity. For a positive defect, the solitons only ex ... [Opt. Express 18, 10956 (2010)] published Wed Jul 7, 2010.
High-repetition-rate pulse generation using dual-mode self-injection locking in a Fabry-Perot laser diode
Xiaohui Fang, P. K. A. Wai, Chao Lu, H. Y. Tam, and Xinyong Dong
A novel and simple method is presented to generate a tunable high-repetition-rate pulse train based on dual-mode self-injection locking of a Fabry-Perot laser diode (FP-LD). Two fiber Bragg gratings (FBGs) are used in the experiment as feedback components. The two self-injection-locked modes evolve ... [Opt. Eng. 49, 074201 (2010)] published Thu Jul 8, 2010.
Supercontinuum conical emission accompanying filamentation of a femtosecond laser pulse in fused quartz
E. O. Smetanina, A. E. Dormidonov, and V. O. Kompanets
The frequency-angular spectrum of the supercontinuum accompanying the filamentation of femtosecond laser pulses in KU-1 fused quartz at various wavelengths has been experimentally and numerically investigated. The splitting effect of divergent conical-emission radiation of the supercontinuum into di ... [J. Opt. Technol. 77, 463 (2010)] published Wed Jul 28, 2010.
Transmission of femtosecond laser pulses through an optical fiber
L. N. Asnis, Ya. V. Grachev, I. Yu. Denisyuk, and O. A. Smolyanskaya
This article discusses questions of how the pulse width of a femtosecond fiber laser, its spectrum, and the envelope of its spectrum vary when the pulse passes through single-mode and multimode quartz optical fibers about 1 m long. ... [J. Opt. Technol. 77, 297 (2010)] published Wed Jul 28, 2010.
Experimental aspects of multiharmonic-order coherent diffractive imaging
Sven Teichmann, Bo Chen, Ruben A. Dilanian, Peter Hannaford, and Lap Van Dao
We describe some experimental aspects required for the implementation of a few-order high-harmonic source for coherent diffractive imaging in the extreme-ultraviolet region. Polychromatic high-angle diffractive images have been successfully processed for both periodic and aperiodic inorganic samples ... [J. Appl. Phys. 108, 023106 (2010)] published Mon Jul 26, 2010.
Ultrabroadband terahertz generation using 4-N,N-dimethylamino-4-N-methyl-stilbazolium tosylate single crystals
I. Katayama, R. Akai, M. Bito, H. Shimosato, K. Miyamoto et al.
Ultrabroadband terahertz generation up to 200 THz has been demonstrated using a 5 fs Ti:sapphire laser and a 4-N,N-dimethylamino-4-N-methyl-stilbazolium tosylate (DAST) crystal. The high-frequency components beyond 100 THz are much stronger than those generated using conventional electro-optic cryst ... [Appl. Phys. Lett. 97, 021105 (2010)] published Wed Jul 14, 2010.
Generation of isolated sub-100-as pulses with 30-fs lasers
Songsong Tang and Xianfeng Chen
We propose a scheme to generate isolated sub-100-as pulses with 30-fs lasers. Our model is based on high-order harmonic generation from a helium atom irradiated by a two-color femtosecond laser field, in which the driving and the control fields are linearly polarized and the polarization angle betwe ... [Phys. Rev. A 82, 013827 ] published .
Wideband amplification using orthogonally polarized pulse trapping in birefringent fibers
Eiji Shiraki and Norihiko Nishizawa
We analyzed the amplification effect of orthogonally polarized pulse trapping in birefringent fibers both experimentally and numerically. Trapped pulses were amplified over a wide wavelength range of 1650-1800 nm accompanying the red-shift. The maximum effective gain was 26 dB for a 140 m-long low b ... [Opt. Express 18, 7323 (2010)] published Wed Jul 7, 2010.
Testing ultrafast two-photon spectral amplitudes via optical fibres
G. Brida, V. Caricato, M. V. Chekhova, M. Genovese, M. Gramegna et al.
We test two-dimensional TPSA of biphoton light emitted via ultrafast spontaneous parametric down-conversion (SPDC) using the effect of group-velocity dispersion in optical fibres. Further, we apply this technique to demonstrate the engineering of biphoton spectral properties by acting on the pump pu ... [Opt. Express 18, 12915 (2010)] published Wed Jul 7, 2010.
Mechanism of depolarization of white light generated by femtosecond laser pulse in water
Jing Yu, Hongbing Jiang, Jing Wen, Hong Yang, and Qihuang Gong
The polarization state of the white light produced by a femtosecond laser pulse through a water cell is investigated. The depolarization of the white light was found to be induced by magnification of the polarization perturbation in the incident light which is caused by the focus lens. Cross-phase m ... [Opt. Express 18, 12581 (2010)] published Wed Jul 7, 2010.
Study on the time-varying and propagating characteristics of ultrashort pulse Laguerre-Gaussian beams
Yi-Dong Liu and Chunqing Gao
This work proposes a simple model of pulse Laguerre-Gaussian Beams (LGBs) by chopping the incident continuous wave LGB into ultrashort pulse. The pulse LGBs are expanded into a series of LGBs with the same angular quantum number (AQN), whose expansion coefficients show the time-varying and propagati ... [Opt. Express 18, 12104 (2010)] published Wed Jul 7, 2010.
Research on Cherenkov second-harmonic generation in periodically poled lithium niobate by femtosecond pulses
Xuewei Deng, Huaijin Ren, Huiying Lao, and Xianfeng Chen
We systematically study the characteristics of the Cherenkov second-harmonic generation in periodically poled lithium niobate by femtosecond pulses. A relatively high conversion efficiency is obtained and what we believe to be a new different explanation is proposed that nonlinearities in the domain ... [J. Opt. Soc. Am. B 27, 1475 (2010)] published Thu Jul 15, 2010.
Energy Exchange between Femtosecond Laser Filaments in Air
Y. Liu, M. Durand, S. Chen, A. Houard, B. Prade et al.
We report on the energy exchange between femtosecond laser filaments in air. A traveling plasma grating formed at the intersection of the filaments is proposed to explain the energy transfer. In this moving plasma grating mediated mechanism the laser energy transfers from the lower frequency pulse t ... [Phys. Rev. Lett. 105, 055003 ] published .
Modulational-instability-induced supercontinuum generation with saturable nonlinear response
R. Vasantha Jayakantha Raja, K. Porsezian, and K. Nithyanandan
We theoretically investigate the supercontinuum generation (SCG) on the basis of modulational instability (MI) in liquid-core photonic crystal fibers (LCPCF) with CS-filled central core. The effect of saturable nonlinearity of LCPCF on SCG in the femtosecond regime is studied using an appropriately ... [Phys. Rev. A 82, 013825 ] published .
Ultrafast double-quantum-coherence spectroscopy of excitons with entangled photons
Marten Richter and Shaul Mukamel
We calculate the four-wave-mixing signal of excitons generated at k=k+k-k by two pulsed entangled photon pairs (k, k) and (k, k), where all four modes are chronologically ordered. Entangled photons offer an unusual combination of bandwidths and temporal resolution not possible by classical beams. Co ... [Phys. Rev. A 82, 013820 ] published .
Gains without inversion in quantum systems with broken parities
W. Z. Jia and L. F. Wei
For a quantum system with broken parity symmetry, selection rules cannot hold and cyclic transition structures are generated. With these loop transitions we discuss how to achieve inversionless gain of the probe field by properly setting the control and auxiliary fields. Possible implementations of ... [Phys. Rev. A 82, 013808 ] published .
Temporal compression of quantum-information-carrying photons using a photon-echo quantum memory approach
S. A. Moiseev and W. Tittel
We study quantum compression and decompression of light pulses that carry quantum information using a photon-echo quantum memory technique with controllable inhomogeneous broadening of an isolated atomic absorption line. We investigate media with differently broadened absorption profiles, transverse ... [Phys. Rev. A 82, 012309 ] published .
Continuous-wave light modulation at molecular frequencies
J. T. Green, J. J. Weber, and D. D. Yavuz
By using continuous-wave (CW)stimulated Raman scattering inside a high-finesse cavity, we generate three CW spectral components covering about one octave of optical bandwidth. We investigate the mutual coherence of these three beams by studying phase-dependent second harmonic generation. From the hi ... [Phys. Rev. A 82, 011805 ] published .
Observation of cooperative Mie scattering from an ultracold atomic cloud
H. Bender, C. Stehle, S. Slama, R. Kaiser, N. Piovella et al.
Scattering of light at a distribution of scatterers is an intrinsically cooperative process, which means that the scattering rate and the angular distribution of the scattered light are essentially governed by bulk properties of the distribution, such as its size, shape, and density, although local ... [Phys. Rev. A 82, 011404 ] published .
Analysis of time-multiplexed optical line-by-line pulse shaping: application for radio-frequency and microwave photonics
Chen-Bin Huang and Andrew M. Weiner
Time-multiplexed optical line-by-line pulse shaping with specific application to rapid update radio-frequency (RF) waveform generation is modeled. The effects of fundamental pulse shaping parameters on generated RF waveforms are numerically analyzed. Experimental and theoretical results are compared ... [Opt. Express 18, 9366 (2010)] published Wed Jul 7, 2010.
A suspended core nanofiber with unprecedented large diameter ratio of holey region to core
Meisong Liao, Chitrarekha Chaudhari, Xin Yan, Guanshi Qin, Chihiro Kito et al.
For a suspended core nanofiber, the holey region is expected to be as large as possible to propagate the light at wavelengths as long as possible. Additionally, a large holey region is significant for its applications in sensors. However, the fabrication of nanofiber with large holey region is still ... [Opt. Express 18, 9088 (2010)] published Wed Jul 7, 2010.
Compact all-fiber high-energy fiber laser with sub-300-fs duration
X. M. Liu and D. Mao
We report a compact all-fiber high-energy fiber laser that consists of a laser oscillator and a compression section. The laser oscillator generates the pulses with high energy and large chirp. The compression section is made of a piece of standard single-mode fiber that dechirps the chirped pulses. ... [Opt. Express 18, 8847 (2010)] published Wed Jul 7, 2010.
Effect of pulse temporal shape on optical trapping and impulse transfer using ultrashort pulsed lasers
Janelle C. Shane, Michael Mazilu, Woei Ming Lee, and Kishan Dholakia
We investigate the effects of pulse duration on optical trappingwith high repetition rate ultrashort pulsed lasers, through Lorentz-Mietheory, numerical simulation, and experiment. Optical trapping experimentsuse a 12 femtosecond duration infrared pulsed laser, with the trappingmicroscope's temporal ... [Opt. Express 18, 7554 (2010)] published Wed Jul 7, 2010.
A dissipative attractor in the spatiotemporal collapse of ultrashort light pulses
Miguel A. Porras
Spatiotemporal self-focusing in nonlinear lossy media pushes ultrashort pulses towards a universal, non-solitary and non-conical light bullet wave state defined by the medium solely, and characterized by maximum energy losses. Its stationary propagation relies on a balance between nonlinear losses a ... [Opt. Express 18, 7376 (2010)] published Wed Jul 7, 2010.
Experimental investigations on nonlinear dynamics in supercontinuum generation with feedback
Nicoletta Brauckmann, Michael Kues, Till Walbaum, Petra Gross, and Carsten Fallnich
A system for supercontinuum generation by using a photonic crystal fiber within a synchronously pumped ring cavity is presented. The feedback led to an interaction of the generated supercontinuum with the following femtosecond laser pulses and thus to the formation of a nonlinear oscillator. The non ... [Opt. Express 18, 7190 (2010)] published Wed Jul 7, 2010.
Tunable narrow band THz wave generation from laser induced gas plasma
Jayashis Das and Masashi Yamaguchi
Tunable narrowband THz waveforms were generated from laser induced gas plasma using shaped optical pulses. Square wave phase patterns were fed to a spatial light modulator. The frequency and amplitude of the square wave phase were used as parameters to tailor the terahertz waveforms. The dependence ... [Opt. Express 18, 7038 (2010)] published Wed Jul 7, 2010.
Nanogratings and nanoholes fabricated by direct femtosecond laser writing in chalcogenide glasses
Qiming Zhang, Han Lin, Baohua Jia, Lei Xu, and Min Gu
We report on the fabrication of sub-wavelength nanostructures on the surface of AsS chalcogenide glasses by appropriately controlling the irradiation condition of single-beam direct femtosecond laser writing. Nanogratings with a period of 180 nm were realized by multipulse irradiation. More importan ... [Opt. Express 18, 6885 (2010)] published Wed Jul 7, 2010.
Generalized Miller Formulae
W. Ettoumi, Y. Petit, J. Kasparian, and J.-P. Wolf
We derive the spectral dependence of the non-linear susceptibility of any order, generalizing the common form of Sellmeier equations. This dependence is fully defined by the knowledge of the linear dispersion of the medium. This finding generalizes the Miller formula to any order of non-linearity. I ... [Opt. Express 18, 6613 (2010)] published Wed Jul 7, 2010.
High speed all optical logic gates based on quantum dot semiconductor optical amplifiers
Shaozhen Ma, Zhe Chen, Hongzhi Sun, and Niloy K. Dutta
A scheme to realize all-optical Boolean logic functions AND, XOR and NOT using semiconductor optical amplifiers with quantum-dot active layers is studied. nonlinear dynamics including carrier heating and spectral hole-burning are taken into account together with the rate equations scheme. Results sh ... [Opt. Express 18, 6417 (2010)] published Wed Jul 7, 2010.
Modulation response of nanoLEDs and nanolasers exploiting Purcell enhanced spontaneous emission
T. Suhr, N. Gregersen, K. Yvind, and J. Mork
The modulation bandwidth of quantum well nanoLED and nanolaser devices is calculated from the laser rate equations using a detailed model for the Purcell enhanced spontaneous emission. It is found that the Purcell enhancement saturates when the cavity quality-factor is increased, which limits the ma ... [Opt. Express 18, 11230 (2010)] published Wed Jul 7, 2010.
Probing and modeling of interfacial carrier motion in organic devices by optical second harmonic generation
Mitsumasa Iwamoto, Takaaki Manaka, Martin Weis, and Dai Taguchi
Here the authors report a novel optical second harmonic generation (SHG) measurement that allows carrier motion in solids to be probed directly. By catching nonlinear polarization induced in the solids by coupling with incident electromagnetic waves (laser beam) and dc electric field from moving car ... [J. Vac. Sci. Technol. B 28, C5F12 (2010)] published Tue Jul 27, 2010.
All-optical memory operation of 980-nm polarization bistable VCSEL for 20-Gb/s PRBS RZ and 40-Gb/s NRZ data signals
Jun Sakaguchi, Takeo Katayama, and Hitoshi Kawaguchi
The fastest known operation of all-optical flip-flop memory was experimentally demonstrated using a 980-nm polarization bistable vertical-cavity surface-emitting laser (VCSEL). Operating conditions of the input signal power and the frequency detuning to achieve the fast optical memory operation were ... [Opt. Express 18, 12362 (2010)] published Wed Jul 7, 2010.
Broad emission band of Yb in the nonlinear Nb:RbTiOPO crystal: origin and applications
J. J. Carvajal, G. Ciatto, X. Mateos, A. Schmidt, U. Griebner et al.
By means of micro-structural and optical characterization of the Yb:Nb:RbTiOPO crystal, we demonstrated that the broad emission band of Yb in these crystals is due to the large splitting of the ytterbium ground state only, and not to a complex multisite occupation by the ytterbium ions in the crysta ... [Opt. Express 18, 7228 (2010)] published Wed Jul 7, 2010.
Photonic generation of ultra-wideband signals by direct current modulation on SOA section of an SOA-integrated SGDBR laser
Hui Lv, Yonglin Yu, Tan Shu, Dexiu Huang, Shan Jiang et al.
Photonic ultra-wideband (UWB) pulses are generated by direct current modulation of a semiconductor optical amplifier (SOA) section of an SOA-integrated sampled grating distributed Bragg reflector (SGDBR) laser. Modulation responses of the SOA section of the laser are first simulated with a microwave ... [Opt. Express 18, 7219 (2010)] published Wed Jul 7, 2010.
Spatially resolved ultrafast transport current in GaAs photoswitches
L. Prechtel, S. Manus, D. Schuh, W. Wegscheider, and A. W. Holleitner
We apply a pump- and probe-scheme to coplanar stripline circuits to investigate the photocurrent response of GaAs photoswitches in time and space. We find a displacement current pulse, as reported earlier. We interpret a time-delayed second pulse as a transport current. In a time-of-flight analysis ... [Appl. Phys. Lett. 96, 261110 (2010)] published Thu Jul 1, 2010.
Tailoring lightmatterspin interactions in colloidal hetero-nanostructures
Jiatao Zhang, Yun Tang, Kwan Lee, and Min Ouyang
The interplay between light and matter is the basis of many fundamental processes and various applications. Harnessing lightmatter interactions in principle allows operation of solid state devices under new physical principles: for example, the a.c. optical Stark effect (OSE) has enabled coherent q ... [Nature 466, 91 (2010)] published Thu Jul 1, 2010.
Multicarrier Recombination and Energy Transfer in Mn-Doped CdS Nanocrystals Studied by Femtosecond PumpProbe Spectroscopy
Seiji Taguchi, Atsushi Ishizumi, and Yoshihiko Kanemitsu
We studied the photocarrier decay dynamics of Mn-doped CdS nanocrystals (NCs) coated with a ZnS shell layer by femtosecond pumpprobe transient absorption spectroscopy. At low excitation intensities, the decay dynamics of photocarriers is determined by energy transfer from electronhole pairs in C ... [J. Phys. Soc. Jpn. 79, 063710 (2010)] published Thu Jul 1, 2010.
Nonlinear spectra of ZnO: reverse saturable, two- and three-photon absorption
M.G. Vivas, T. Shih, T. Voss, E. Mazur, and C. R. Mendonca
We present a broadband (460 - 980 nm) analysis of the nonlinear absorption processes in bulk ZnO, a large-bandgap material with potential blue-to-UV photonic device applications. Using an optical parametric amplifier we generated tunable 1-kHz repetition rate laser pulses and employed the Z-scan tec ... [Opt. Express 18, 9628 (2010)] published Wed Jul 7, 2010.
Ultrafast amorphization in GeSbTe thin film induced by single femtosecond laser pulse
Mitsutaka Konishi, Hisashi Santo, Yuki Hongo, Kazuyuki Tajima, Masaharu Hosoi et al.
We demonstrate amorphization in a GeSbTe (GST) thin film through a nonthermal process by femtosecond electronic excitation. Amorphous recording marks were formed by irradiation with a single femtosecond pulse, and were confirmed to be recrystallized by laser thermal annealing. Scanning electron micr ... [Appl. Opt. 49, 3470 (2010)] published Wed Jul 7, 2010.
High pressure effect on the ultrafast energy relaxation rate of LDS698 (CHNOCl) in a solution
Bingguo Liu, Chunyuan He, Mingxing Jin, Qiaoqiao Wang, Sheng Hsien Lin et al.
Effects of high pressure in a range of up to 1.7 GPa on ultrafast energy relaxation of LDS698 (CHNOCl) molecules in solution have experimentally been illustrated by a method of femtosecond time-resolved absorption spectroscopy. The rates of the intramolecular and intermolecular energy relaxations sh ... [Opt. Express 18, 6863 (2010)] published Wed Jul 7, 2010.
Laser turns silicon superwicking
A. Y. Vorobyev and Chunlei Guo
Using high-intensity femtosecond laser pulses, we create a novel surface pattern that transforms regular silicon to superwicking. Due to the created surface structure, water sprints vertically uphill in a gravity defying way. Our study of the liquid motion shows that the fast self-propelling motion ... [Opt. Express 18, 6455 (2010)] published Wed Jul 7, 2010.
Optical fiber link for transmission of 1-nJ femtosecond laser pulses at 1550 nm
Finn Eichhorn, Rasmus Kjelsmark Olsson, Jonas C. D. Buron, Lars Gruner-Nielsen, Jens Engholm Pedersen et al.
We report on numerical and experimental characterization of the performance of a fiber link optimized for the delivery of sub-100-fs laser pulses at 1550 nm over several meters of fiber. We investigate the power handling capacity of the link, and demonstrate all-fiber delivery of 1-nJ pulses over a ... [Opt. Express 18, 6978 (2010)] published Wed Jul 7, 2010.
Two-photon spectral hole burning spectroscopy of InAs/GaAs quantum dots
T. Moldaschl, W. Parz, T. Muller, S. Golka, G. Strasser et al.
Femtosecond spectral hole burning experiments were performed on InAs/GaAs quantum dots to investigate the influence of high excitation intensities. The observation of additional spectral holes, as well as distinct absorption line broadening are both attributed to two-photon absorption processes. The ... [Appl. Phys. Lett. 97, 011903 (2010)] published Wed Jul 7, 2010.
Probing valence band structure in wurtzite InP nanowires using excitation spectroscopy
S. Perera, K. Pemasiri, M. A. Fickenscher, H. E. Jackson, L. M. Smith et al.
We use time-resolved photoluminescence spectroscopy and photoluminescence excitation spectroscopy to measure the valence band parameters of hexagonal wurtzite InP nanowires. The A exciton emission and excitation energy is observed at 1.504 eV as expected. Excitation spectra show that the B and C hol ... [Appl. Phys. Lett. 97, 023106 (2010)] published Wed Jul 14, 2010.
Electron-Hole Overlap Dictates the Hole Spin Relaxation Rate in Nanocrystal Heterostructures
Jun He, Haizheng Zhong, and Gregory D. Scholes
Hole spin relaxation dynamics in CdTe/CdSe core-shell nanocrystals are measured by an ultrafast polarization transient grating technique. Photoexcited charge separation in type II structures suppresses the electron-hole exchange interaction and the hole spin relaxation time constant is found to incr ... [Phys. Rev. Lett. 105, 046601 ] published .
Superdiffusive Spin Transport as a Mechanism of Ultrafast Demagnetization
M. Battiato, K. Carva, and P. M. Oppeneer
We propose a semiclassical model for femtosecond laser-induced demagnetization due to spin-polarized excited electron diffusion in the superdiffusive regime. Our approach treats the finite elapsed time and transport in space between multiple electronic collisions exactly, as well as the presence of ... [Phys. Rev. Lett. 105, 027203 ] published .
Band-dependent Quasiparticle Dynamics in Single Crystals of the BaKFeAs Superconductor Revealed by Pump-Probe Spectroscopy
Darius H. Torchinsky, G. F. Chen, J. L. Luo, N. L. Wang, and Nuh Gedik
We report on band-dependent quasiparticle dynamics in BaKFeAs (T=37 K) measured using ultrafast pump-probe spectroscopy. In the superconducting state, we observe two distinct relaxation processes: a fast component whose decay rate increases linearly with excitation density and a slow component with ... [Phys. Rev. Lett. 105, 027005 ] published .
Optical detection of folded mini-zone-edge coherent acoustic modes in a doped GaAs/AlAs superlattice
R. Beardsley, A. V. Akimov, B. A. Glavin, W. Maryam, M. Henini et al.
A coherent phonon mode with frequency corresponding to the first mini Brillouin-zone edge stop gap is observed in ultrafast pump-probe measurements on a doped semiconductor superlattice structure. It is proposed that the optical detection of the mode is facilitated by interactions with the free carr ... [Phys. Rev. B 82, 041302 ] published .
Optical emission and nanoparticle generation in Al plasmas using ultrashort laser pulses temporally optimized by real-time spectroscopic feedback
M. Guillermin, J. P. Colombier, S. Valette, E. Audouard, F. Garrelie et al.
With an interest in pulsed laser deposition and remote spectroscopy techniques, we explore here the potential of laser pulses temporally tailored on ultrafast time scales to control the expansion and the excitation degree of various ablation products including atomic species and nanoparticulates. Ta ... [Phys. Rev. B 82, 035430 ] published .
Coherent control of metallic nanoparticles near fields: Nanopulse controllers and functional nanoamplifiers
S. M. Sadeghi
When a hybrid system consisting of a metallic nanoparticle and a semiconductor quantum dot interacts with a coherent light source (laser beam) the coherence generated in the quantum dot can significantly renormalize the plasmonic field. In this paper we study the impacts of such coherent-plasmonic p ... [Phys. Rev. B 82, 035413 ] published .
Optically induced anisotropy of surface plasmons in spherical metal nanoparticles
Igor Dmitruk, Ivan Blonskiy, Ihor Pavlov, Oleg Yeshchenko, Alexandr Alexeenko et al.
Red shift and splitting of surface plasmon band in absorption spectra of copper nanoparticles incorporated in silica matrix have been observed under irradiation by intense femtosecond laser pulse with power density 1010 W/cm. These phenomena are interpreted as a result of change of dielectric const ... [Phys. Rev. B 82, 033401 ] published .
Stochastic heating of a molecular nanomagnet
L. Chotorlishvili, P. Schwab, Z. Toklikishvili, and J. Berakdar
We study the excitation dynamics of a single molecular nanomagnet by static and pulsed magnetic fields. Based on a stability analysis of the classical magnetization dynamics we identify analytically the fields parameters for which the energy is stochastically pumped into the system in which case the ... [Phys. Rev. B 82, 014418 ] published .
Room temperature terahertz electro-optic modulation by excitons in carbon nanotubes
T. Ogawa, S. Watanabe, N. Minami, and R. Shimano
We have investigated the electroabsorption of aligned micelle-wrapped single-walled carbon nanotubes induced by intense terahertz (THz) pulses by using THz-pump and optical-probe spectroscopy at room temperature. The electroabsorption signal is enhanced at exciton resonances near the optical communi ... [Appl. Phys. Lett. 97, 041111 (2010)] published Tue Jul 27, 2010.
Strong spin-lattice coupling in multiferroic hexagonal manganite YMnO probed by ultrafast optical spectroscopy
Kyeong-Jin Jang, Han-gyoel Lee, Sangkyung Lee, Jaewook Ahn, Jai Seok Ahn et al.
We report the observation of spin-lattice coupling in multiferroic YMnO by femtosecond near-infrared pump and probe spectroscopy. A coherent 31 GHz acoustic phonon was detected above the magnetic ordering temperature, and a higher frequency coherent mode was observed in the antiferromagnetic phase. ... [Appl. Phys. Lett. 97, 031914 (2010)] published Thu Jul 22, 2010.
Intrinsic geometric scattering probed by picosecond optoacoustics in a cylindrical cavity: Application to acoustic and optical characterizations of a single micron carbon fiber
D. Segur, Y. Guillet, and B. Audoin
A picosecond pump-probe technique is used to reveal the optoacoustic response of a single micrometric carbon fiber. The signature of the intrinsic geometric scattering resulting from acoustic reflections at free surface of the cylindrical cavity is contained in the signals. The fiber transverse elas ... [Appl. Phys. Lett. 97, 031901 (2010)] published Mon Jul 19, 2010.
Nonreciprocal emission of spin-wave packet in FeNi film
K. Sekiguchi, K. Yamada, S. M. Seo, K. J. Lee, D. Chiba et al.
We report a time-resolved propagating spin wave spectroscopy for FeNi film. We show that the amplitude of the spin-wave packet depends on the direction of magnetization and that its phase can be controlled by the polarity of pulsed magnetic field for the excitation. The nonreciprocal emission of spi ... [Appl. Phys. Lett. 97, 022508 (2010)] published Thu Jul 15, 2010.
Long exciton spin relaxation in coupled quantum wells
K. Kowalik-Seidl, X. P. Vogele, B. N. Rimpfl, S. Manus, J. P. Kotthaus et al.
Spatially indirect excitons in a coupled quantum well structure were studied by means of polarization and time-resolved photoluminescence. A strong degree of circular polarization (>50%) in emission was achieved when the excitation energy was tuned into resonance with the direct exciton state. The i ... [Appl. Phys. Lett. 97, 011104 (2010)] published Thu Jul 8, 2010.
Direct observation of low frequency confined acoustic phonons in silver nanoparticles: Terahertz time domain spectroscopy
Sunil Kumar, N. Kamaraju, B. Karthikeyan, M. Tondusson, E. Freysz et al.
Terahertz time domain spectroscopy has been used to study low frequency confined acoustic phonons of silver nanoparticles embedded in poly(vinyl alcohol) matrix in the spectral range of 0.12.5 THz. The real and imaginary parts of the dielectric function show two bands at 0.60 and 2.12 THz attributed ... [J. Chem. Phys. 133, 014502 (2010)] published Fri Jul 2, 2010.
Electron-phonon coupling and the charge gap of spin-density wave iron-pnictide materials from quasiparticle relaxation dynamics
L. Stojchevska, P. Kusar, T. Mertelj, V. V. Kabanov, X. Lin et al.
We investigate the quasiparticle relaxation and low-energy electronic structure in undoped SrFeAs exhibiting spin-density wave (SDW) ordering using optical pump-probe femtosecond spectroscopy. A remarkable critical slowing down of the quasiparticle relaxation dynamics at the SDW transition temperatu ... [Phys. Rev. B 82, 012505 ] published .
Fidelity susceptibility approach to quantum phase transitions in the XY spin chain with multisite interactions
W. W. Cheng and J.-M. Liu
We study the quantum critical behavior of the XY spin chain with multisite interaction by means of a fidelity susceptibility (FS) calculation. The key ingredients (e.g., finite-size scaling behavior, universality principle) of the quantum criticality near the critical point are investigated carefull ... [Phys. Rev. A 82, 012308 ] published .
Terahertz generation based on an optically pumped ballistic electron wave swing device
D. Dragoman, M. Dragoman, and H. Hartnagel
Terahertz (THz) signals can be generated by the periodic motion of ballistic electron bunches inside a quantum well cavity surrounded by two asymmetric resonant tunneling structure implemented in an InAlAs/InGaAs heterostructure. The electron bunches are produced in an adjacent active quantum well b ... [J. Appl. Phys. 108, 026103 (2010)] published Tue Jul 27, 2010.
Field-dependent ultrafast dynamics and mechanism of magnetization reversal across ferrimagnetic compensation points in GdFeCo amorphous alloy films
Zhifeng Chen, Ruixin Gao, Zixin Wang, Chudong Xu, Daxin Chen et al.
Ultrafast dynamics of genuine magneto-optical recording across ferrimagnetic compensation points is demonstrated in GdFeCo films using time-resolved polar Kerr spectroscopy combined with a laser-synchronized sinusoidal alternating magnetic field which can reinitialize irreversible initial magnetizat ... [J. Appl. Phys. 108, 023902 (2010)] published Fri Jul 16, 2010.
Fast and slow carrier recombination transients in highly excited 4H and 3CSiC crystals at room temperature
P. SCajev, V. Gudelis, K. Jarasiunas, and P. B. Klein
Nonequilibrium carrier recombination in highly excited epitaxial layers of 4HSiC and free standing 3CSiC was analyzed numerically and studied experimentally by the time-resolved free carrier absorption (FCA) technique. The measurement setup combined interband carrier excitation by a picosecond laser ... [J. Appl. Phys. 108, 023705 (2010)] published Tue Jul 27, 2010.
Ultrafast observation of shocked states in a precompressed material
Michael R. Armstrong, Jonathan C. Crowhurst, Sorin Bastea, and Joseph M. Zaug
We apply ultrafast single shot interferometry to determine the pressure and density of argon shocked from up to 7.8 GPa static initial pressure in a diamond anvil cell. This method enables the observation of thermodynamic states distinct from those observed in either single shock or isothermal compr ... [J. Appl. Phys. 108, 023511 (2010)] published Tue Jul 27, 2010.
Dynamics of polarized photoluminescence in m-plane InGaN/GaN quantum wells
Vytautas Liuolia, Saulius MarcinkeviCius, You-Da Lin, Hiroaki Ohta, Steven P. DenBaars et al.
Spectrally-, polarization-, and time-resolved photoluminescence (PL) experiments have been performed on 2.5 nm thick m-plane single InGaN quantum wells. It has been found that PL decay is mainly determined by nonradiative recombination through several types of recombination centers, while PL rise is ... [J. Appl. Phys. 108, 023101 (2010)] published Fri Jul 16, 2010.
Radiation efficiency of heavily doped bulk n-InP semiconductor
Oleg Semyonov, Arsen Subashiev, Zhichao Chen, and Serge Luryi
Recombination of minority carriers in heavily doped n-InP wafers has been investigated using spectral and time-resolved photoluminescence at different temperatures. Studies of the transmitted luminescence were enabled by the partial transparency of the samples due to the MossBurstein effect. Tempora ... [J. Appl. Phys. 108, 013101 (2010)] published Thu Jul 1, 2010.
Carrier dynamics in isoelectronic ZnSeO semiconductors
Y. C. Lin, H. L. Chung, W. C. Chou, W. K. Chen, W. H. Chang et al.
This study explores the effects of both Oxygen and temperature on the carrier dynamics of isoelectronic ZnSeO (x=0.027 and 0.053) semiconductors using photoluminescence (PL) and time-resolved PL spectroscopy. We find that the Kohlrausch law is highly consistent with the complex decay traces induced ... [Appl. Phys. Lett. 97, 041909 (2010)] published Thu Jul 29, 2010.
Controllable chirality switching of a moving domain wall by oblique magnetic field
Soo-Man Seo, Kyung-Jin Lee, Soon-Wook Jung, and Hyun-Woo Lee
A full micromagnetic model and a simplified one-dimensional analytical model are used to investigate the domain wall dynamics driven by an oblique magnetic field. Both models show that the Walker breakdown [N. L. Schryer and L. R. Walker, J. Appl. Phys. 45, 5406 (1974)] can occur at two distinct fie ... [Appl. Phys. Lett. 97, 032507 (2010)] published Fri Jul 23, 2010.
Femtosecond laser near-field nanoablation patterning using Mie resonance high dielectric constant particle with small size parameter
Yuto Tanaka, Go Obara, Akira Zenidaka, Mitsuhiro Terakawa, and Minoru Obara
We demonstrate near-field nanohole patterning using a Mie resonance, small size parameter particle for nanofabrication technology regardless of substrate's refractive index. Maximal enhancement factor and nearly smallest spot diameter among the same size dielectric particles are simultaneously obtai ... [Appl. Phys. Lett. 96, 261103 (2010)] published Tue Jun 29, 2010.
Ultrafast All-Optical Coupling of Light to Surface Plasmon Polaritons on Plain Metal Surfaces
Nir Rotenberg, Markus Betz, and Henry M. van Driel
We propose and demonstrate an ultrafast all-optical method to couple light to surface plasmon polaritons on planar gold films. By interfering two 150 fs, 810 nm pulses we excite a transient grating in the temperature of the free electrons of the metal, resulting in a grating in the dielectric functi ... [Phys. Rev. Lett. 105, 017402 ] published .
On femtosecond micromachining of HPHT single-crystal diamond with direct laser writing using tight focusing
Othman H. Y. Zalloum, Matthew Parrish, Alexander Terekhov, and William Hofmeister
We investigate the formation of diversiform micro-/nano-structures in High-Pressure High-Temperature (HPHT) synthetic single-crystal diamond by tight-focusing 200 fs regeneratively amplified Ti: Sapphire laser pulses centered at lambda = 800 nm. Ablated samples of synthetic single crystal nanodiamon ... [Opt. Express 18, 13122 (2010)] published Wed Jul 7, 2010.
Geometrical Resonance Conditions for THz Radiation from the Intrinsic Josephson Junctions in BiSrCaCuO
Manabu Tsujimoto, Kazuhiro Yamaki, Kota Deguchi, Takashi Yamamoto, Takanari Kashiwagi et al.
Subterahertz radiation emitted from a variety of short rectangular-, square-, and disk-shaped mesas of intrinsic Josephson junctions fabricated from a BiSrCaCuO single crystal was studied from the observed I-V characteristics, far-infrared spectra, and spatial radiation patterns. In all cases, the r ... [Phys. Rev. Lett. 105, 037005 ] published .
Thermoelastic analysis of a silicon surface under x-ray free-electron-laser irradiation
A. R. B. de Castro, Aurea R. Vasconcellos, and Roberto Luzzi
We present an analysis of the time evolution of a highly excited silicon substrate after partial absorption of a femtosecond soft x-ray pulse. The detailed time-dependent thermoelastic behavior of the substrate in terms of the displacements u(r,t) is derived for time delays for which the usual local ... [Rev. Sci. Instrum. 81, 073102 (2010)] published Thu Jul 8, 2010.
Following a chemical reaction using high-harmonic interferometry
H. J. Wrner, J. B. Bertrand, D. V. Kartashov, P. B. Corkum, and D. M. Villeneuve
The study of chemical reactions on the molecular (femtosecond) timescale typically uses pump laser pulses to excite molecules and subsequent probe pulses to interrogate them. The ultrashort pump pulse can excite only a small fraction of molecules, and the probe wavelength must be carefully chosen t ... [Nature 466, 604 (2010)] published Thu Jul 29, 2010.
Control of ionization and dissociation by optical pulse trains
A. Kirrander, Ch. Jungen, and H. H. Fielding
Ever since the first lasers were built over 40 years ago, chemists and physicists have been attempting to exploit them as tools for controlling the outcome of chemical reactions. Over the last decade this dream has become a reality. The most successful approaches have employed learning algorithms to ... [Phys. Chem. Chem. Phys. 12, 8948 (2010)] published Thu Jul 29, 2010.
Doppler effect in fragment autoionization following core-to-Rydberg excitations of N
Eiji Shigemasa, Tatsuo Kaneyasu, Tomohiro Matsushita, Yusuke Tamenori, and Yasumasa Hikosaka
The autoionization of atomic fragments after core-to-Rydberg excitations in N has been studied using high-resolution electron spectroscopy. Doppler profiles are clearly observed on atomic autoionization peaks and show dependence on the symmetries of the excited states. It is demonstrated that inform ... [New J. Phys. 12, 063030 (2010)] published Thu Jul 1, 2010.
Momentum space analysis of multiphoton double ionization of helium by intense attosecond xuv pulses
Zheng Zhang, Liang-You Peng, Qihuang Gong, and Toru Morishita
We investigate the momentum and energy distributions of the two electrons in multiphoton double ionization of He by intense attosecond xuv pulses, based on a two-dimensional model. Two different patterns of the momentum distributions are identified, corresponding to the uncorrelated and correlated c ... [Opt. Express 18, 8976 (2010)] published Wed Jul 7, 2010.
Molecular high harmonic generation in a two-color field
Pengfei Wei, Candong Liu, Chunmei Zhang, Yansui Huang, Yuxin Leng et al.
We experimentally investigate the high harmonic generation (HHG) from CH molecules and Xe atoms in a two-color field (using the 800nm laser and the tunable laser with the longer wavelength from 1500nm to 1900nm), and observe that the longer wavelength component can destructively suppress the HHG fro ... [Opt. Express 18, 11664 (2010)] published Wed Jul 7, 2010.
Mapping Molecular Orbital Symmetry on High-Order Harmonic Generation Spectrum Using Two-Color Laser Fields
Hiromichi Niikura, Nirit Dudovich, D. M. Villeneuve, and P. B. Corkum
We have measured high-order harmonic generation spectra of D, N, and CO by mixing orthogonally polarized 800 and 400 nm laser fields. The intensity of the high-harmonic spectrum is modulated as we change the relative phase of the two pulses. For randomly orientated molecules, the phase of the intens ... [Phys. Rev. Lett. 105, 053003 ] published .
Attosecond Electron Spectroscopy Using a Novel Interferometric Pump-Probe Technique
J. Mauritsson, T. Remetter, M. Swoboda, K. Klunder, A. L'Huillier et al.
We present an interferometric pump-probe technique for the characterization of attosecond electron wave packets (WPs) that uses a free WP as a reference to measure a bound WP. We demonstrate our method by exciting helium atoms using an attosecond pulse (AP) with a bandwidth centered near the ionizat ... [Phys. Rev. Lett. 105, 053001 ] published .
Tracking Autoionizing-Wave-Packet Dynamics at the 1-fs Temporal Scale
E. Skantzakis, P. Tzallas, J. E. Kruse, C. Kalpouzos, O. Faucher et al.
We present time-resolved studies and Fourier transform spectroscopy of inner-shell excited states undergoing Auger decay and doubly excited autoionizing states, utilizing coherent extreme-ultraviolet (XUV) radiation continua. Series of states spanning a range of ~4 eV are excited simultaneously. An ... [Phys. Rev. Lett. 105, 043902 ] published .
Isotope effects in the harmonic response from hydrogenlike muonic atoms in strong laser fields
Atif Shahbaz, Thomas J. Burvenich, and Carsten Muller
High-order harmonic generation from hydrogenlike muonic atoms exposed to ultraintense high-frequency laser fields is studied. Systems of low nuclear-charge number Z are considered where a nonrelativistic description applies. By comparing the radiative response for different isotopes, we demonstrate ... [Phys. Rev. A 82, 013418 ] published .
Theory of probing attosecond electron wave packets via two-path interference of angle-resolved photoelectrons
N. N. Choi, T. F. Jiang, T. Morishita, M.-H. Lee, and C. D. Lin
We study theoretically the electron wave packet generated by an attosecond pulse train (APT) which is probed with a time-delayed infrared (IR) laser pulse. The APT creates an excited state and a continuum electron wave packet. By ionizing the excited state with an IR, a delayed new continuum electro ... [Phys. Rev. A 82, 013409 ] published .
Designing of transparency windows by quantum interference of wave packets
Krishna Rai Dastidar and Anindita Bhattacharjee
It has been shown that control over the design of single- or multimode-transparency windows can be achieved by control-probe quantum interferometry using two delayed phase-locked ultrashort pulses. We have investigated how single- or multimode-transparency windows can be designed by eliminating the ... [Phys. Rev. A 82, 013404 ] published .
Mechanisms underlying strong-field double ionization of argon dimers
B. Manschwetus, H. Rottke, G. Steinmeyer, L. Foucar, A. Czasch et al.
We investigate double ionization of argon dimers in high-intensity ultrashort Ti:sapphire laser pulses. We are able to identify several strong-field excitation pathways of the dimer that terminate in atomic ion pairs from a Coulomb explosion. The explosion starts from two-site double-ionized dimers ... [Phys. Rev. A 82, 013413 ] published .
Photodissociation dynamics of acetylene via the C-tilde Pi electronic state
Yongwei Zhang, Kaijun Yuan, Shengrui Yu, David H. Parker, and Xueming Yang
Photodissociation of acetylene has been studied using the H-atom Rydberg tagging time-of-flight technique at two excitation wavelengths (148.35 and 151.82 nm) in the vacuum ultraviolet region. Product translational energy distributions have been obtained from the H-atom time-of-flight spectra. Exper ... [J. Chem. Phys. 133, 014307 (2010)] published Wed Jul 7, 2010.
Real-time dissociation dynamics of the NeBr van der Waals complex
Jordan M. Pio, Molly A. Taylor, Wytze E. van der Veer, Craig R. Bieler, Jose A. Cabrera et al.
We have characterized the vibrational predissociation (VP) of the NeBr van der Waals complex using time- and frequency-resolved pump-probe spectroscopy. After exciting Br within the complex to a vibrational level 16<=nu<=23 in the B state, we follow the flow of halogen vibrational energy to the van ... [J. Chem. Phys. 133, 014305 (2010)] published Wed Jul 7, 2010.
Steplike Intensity Threshold Behavior of Extreme Ionization in Laser-Driven Xenon Clusters
T. Doppner, J. P. Muller, A. Przystawik, S. Gode, J. Tiggesbaumker et al.
The generation of highly charged Xe ions up to q=24 is observed in Xe clusters embedded in helium nanodroplets and exposed to intense femtosecond laser pulses (lambda=800 nm). Laser intensity resolved measurements show that the high-q ion generation starts at an unexpectedly low threshold intensity ... [Phys. Rev. Lett. 105, 053401 ] published .
Newton's Cradle and Entanglement Transport in a Flexible Rydberg Chain
S. Wuster, C. Ates, A. Eisfeld, and J. M. Rost
In a regular, flexible chain of Rydberg atoms, a single electronic excitation localizes on two atoms that are in closer mutual proximity than all others. We show how the interplay between excitonic and atomic motion causes electronic excitation and diatomic proximity to propagate through the Rydberg ... [Phys. Rev. Lett. 105, 053004 ] published .
Ionization Branching Ratio Control with a Resonance Attosecond Clock
Luca Argenti and Eva Lindroth
We investigate the possibility to monitor the dynamics of autoionizing states in real-time and control the yields of different ionization channels in helium by simulating extreme ultraviolet (XUV) pump IR-probe experiments focused on the N=2 threshold. The XUV pulse creates a coherent superposition ... [Phys. Rev. Lett. 105, 053002 ] published .
Simulation of the above-threshold-ionization experiment using the molecular strong-field approximation: The choice of gauge
M. Busuladzic and D. B. Milosevic
We investigate how various versions of the molecular strong-field approximation (MSFA) agree with the experiment by Grasbon et al. [Phys. Rev. A 63, 041402(R) (2001)], in which the suppression of the ionization yield in the low-energy spectrum of the O molecule, compared to the spectrum of its compa ... [Phys. Rev. A 82, 015401 ] published .
Recoil effects in multiphoton electron-positron pair creation
K. Krajewska and J. Z. Kaminski
Triply differential probability rates for electron-positron pair creation in laser-nucleus collisions, calculated within the S-matrix approach, are investigated as functions of the nuclear recoil. Pronounced enhancements of differential probability rates of multiphoton pair production are found for ... [Phys. Rev. A 82, 013420 ] published .
Time-dependent analysis of few-photon coherent control schemes
Shaohao Chen, Agnieszka Jaron-Becker, and Andreas Becker
We investigate the coherent control of nonresonant two-photon excitation and (2+1) photon ionization processes from the time-dependent perspective. To this end, we have solved the time-dependent Schrodinger equation for a hydrogen atom interacting with an ultraviolet laser field. Results are obtaine ... [Phys. Rev. A 82, 013414 ] published .
Implementation of a single femtosecond optical frequency comb for rovibrational cooling
W. Shi and S. Malinovskaya
We show that a single femtosecond optical frequency comb may be used to induce two-photon transitions between molecular vibrational levels to form ultracold molecules (e.g., KRb). The phase across an individual pulse in the pulse train is sinusoidally modulated with a carefully chosen modulation amp ... [Phys. Rev. A 82, 013407 ] published .
Unified understanding of tunneling ionization and stabilization of atomic hydrogen in circularly and linearly polarized intense laser fields
Haruhide Miyagi and Kiyohiko Someda
On the basis of the Floquet formalism, the ionization mechanisms of atomic hydrogen in circularly and linearly polarized intense laser fields are discussed. By using the complex scaling method in the velocity gauge, the pole positions of the scattering-matrix on the complex quasienergy Riemann surfa ... [Phys. Rev. A 82, 013402 ] published .
Interpretation of the Si Kalpha x-ray spectra accompanying the stopping of swift Ca ions in low-density SiO aerogel
J. Rzadkiewicz, A. Gojska, O. Rosmej, M. Polasik, and K. Slabkowska
This article presents a detailed analysis of the Kalpha x-ray spectra of Si induced by 11.4 MeV/u Ca projectiles penetrating a low-density SiO aerogel target measured with high spectral and spatial resolution at the UNILAC accelerator at GSI-Darmstadt. The low-density material used in the experiment ... [Phys. Rev. A 82, 012703 ] published .
Internuclear-distance dependence of electron correlation in nonsequential double ionization of H
Aihong Tong, Qing Liao, Yueming Zhou, and Peixiang Lu
Using three-dimensional classical ensembles, we have investigated the internuclear distance dependence of nonsequential double ionization (NSDI) of H molecules by an 800 nm, 1 x 10 W/cm laser pulse. For the internuclear distance R ranging from 2 to 12 a.u., the NSDI of H provides rich correlation pa ... [Opt. Express 18, 9064 (2010)] published Wed Jul 7, 2010.
Effect of pure dephasing on the Jaynes-Cummings nonlinearities
A. Gonzalez-Tudela, E. del Valle, E. Cancellieri, C. Tejedor, D. Sanvitto et al.
We study the effect of pure dephasing on a two-level system in strong coupling in the nonlinear regime with the single mode of a cavity. The photoluminescence spectrum of the cavity has a robust tendency to display triplet structures, instead of the expected Jaynes-Cummings pairs of doublets at the ... [Opt. Express 18, 7002 (2010)] published Wed Jul 7, 2010.
Ultrafast Interatomic Electronic Decay in Multiply Excited Clusters
Alexander I. Kuleff, Kirill Gokhberg, Soren Kopelke, and Lorenz S. Cederbaum
An ultrafast mechanism belonging to the family of interatomic Coulombic decay (ICD) phenomena is proposed. When two excited species are present, an ultrafast energy transfer can take place bringing one of them to its ground state and ionizing the other one. It is shown that if large homoatomic clust ... [Phys. Rev. Lett. 105, 043004 ] published .
Alignment-dependent ionization of molecular hydrogen in intense laser fields
Yulian V. Vanne and Alejandro Saenz
The alignment dependence of the ionization behavior of H exposed to intense ultrashort laser pulses is investigated on the basis of solutions of the full time-dependent Schrodinger equation within the fixed-nuclei and dipole approximation. The total ionization yields as well as the energy-resolved e ... [Phys. Rev. A 82, 011403 ] published .
Double-ionization mechanisms of the argon dimer in intense laser fields
B. Ulrich, A. Vredenborg, A. Malakzadeh, M. Meckel, K. Cole et al.
We have measured the two-site double ionization of argon dimers by ultrashort laser pulses leading to fragmentation into two singly charged argon ions. Contrary to the expectations from a pure Coulomb explosion following rapid removal of one electron from each of the atoms, we find three distinct pe ... [Phys. Rev. A 82, 013412 ] published .
Two-Photon Inner-Shell Ionization in the Extreme Ultraviolet
V. Richardson, J. T. Costello, D. Cubaynes, S. Dusterer, J. Feldhaus et al.
We have observed the simultaneous inner-shell absorption of two extreme-ultraviolet photons by a Xe atom in an experiment performed at the short-wavelength free electron laser facility FLASH. Photoelectron spectroscopy permitted us to unambiguously identify a feature resulting from the ionization of ... [Phys. Rev. Lett. 105, 013001 ] published .
Nonlinear Fourier-transform spectroscopy of D using high-order harmonic radiation
Yusuke Furukawa, Yasuo Nabekawa, Tomoya Okino, Sebastien Saugout, Kaoru Yamanouchi et al.
We have determined the multiphoton ionization and dissociation pathways of D with the simultaneous irradiation of the high-order harmonic fields and the low-order harmonic fields of Ti:sapphire laser pulses in the visible-vacuum ultraviolet region with the aid of a nonlinear Fourier-transform spectr ... [Phys. Rev. A 82, 013421 ] published .
Creation of multihole molecular wave packets via strong-field ionization
Dominik Geissler, Tamas Rozgonyi, Jesus Gonzalez-Vazquez, Leticia Gonzalez, Sarah Nichols et al.
We demonstrate the creation of vibrational wave packets on multiple electronic states of a molecule via strong-field ionization. Furthermore, we show that the relative contribution of the different electronic states depends on the shape of the laser pulse which launches the wave packets. ... [Phys. Rev. A 82, 011402 ] published .
Long-lived quantum coherence in photosynthetic complexes at physiological temperature
Gitt Panitchayangkoon, Dugan Hayes, Kelly A. Fransted, Justin R. Caram, Elad Harel et al.
Photosynthetic antenna complexes capture and concentrate solar radiation by transferring the excitation to the reaction center that stores energy from the photon in chemical bonds. This process occurs with near-perfect quantum efficiency. Recent experiments at cryogenic temperatures have revealed t ... [Proc. Natl. Acad. Sci. U.S.A. 107, 12766 (2010)] published Mon Jul 26, 2010.
Ultrafast reversible ligand isomerisation in Na[Fe(CN)NO]2HO single crystals
Dominik Schaniel, Matthieu Nicoul, and Theo Woike
We present a time-resolved absorption study on the light-induced generation of reversible linkage NO isomers in single crystals of Na[Fe(CN)NO]2HO using laser pulses of 160 fs width. Using the pump wavelength lambda = 500 nm the singletsinglet A-->E excitation induces the NO rotation by about 90 deg ... [Phys. Chem. Chem. Phys. 12, 9029 (2010)] published Thu Jul 29, 2010.
Ring-puckering motion in cyclopentene studied by time-resolved rotational coherence spectroscopy and ab initio calculations
Maksim Kunitski, Stefan Knippenberg, Maxim Gelin, Christoph Riehn, Andreas Dreuw et al.
The ring-puckering vibration in cyclopentene was studied by rotational time-resolved femtosecond degenerate four-wave mixing (fs DFWM) spectroscopy. The fs DFWM spectra of cyclopentene were measured both in a supersonic expansion and in a gas cell at room temperature. The room temperature fs DFWM sp ... [Phys. Chem. Chem. Phys. 12, 8190 (2010)] published Thu Jul 15, 2010.
Interrogating the ultrafast dynamics of an efficient dye for sunlight conversion
Marcin Ziolek, Xichuan Yang, Licheng Sun, and Abderrazzak Douhal
We report on studies of the recently synthesized compound (TPC1) with a promising potential use in dye-sensitized solar cells. We used steady-state as well as femtosecond (fs) to nanosecond (ns) time-resolved emission techniques to understand its behaviour under different conditions of solvation and ... [Phys. Chem. Chem. Phys. 12, 8098 ] published .
Photophysics of aromatic thiourea derivatives and their complexes with anions. Fast and ultrafast spectroscopic investigations
Tiziana Del Giacco, Benedetta Carlotti, Stefano De Solis, Arianna Barbafina, and Fausto Elisei
In order to collect detailed information on the interaction mechanism between fluorescent thiourea derivatives and anions, 9-[4-(trifluoromethyl)phenylthioureidomethyl]anthracene (1) and the corresponding 10-cyanoanthracene derivative (2) were synthesized and investigated in DMSO and MeCN by using a ... [Phys. Chem. Chem. Phys. 12, 8062 ] published .
Femtosecond time-resolved photophysics and photodissociation dynamics of 1-iodonaphthalene
Raul Montero, Alvaro Peralta Conde, Asier Longarte, Fernando Castano, Maria E. Corrales et al.
The ultrafast relaxation of 1-iodonaphthalene, with particular attention to the dissociation channels, has been studied by time-resolved femtosecond pumpprobe mass spectrometry following excitation at 267 and 317 nm. The measured transients for the parent ion and the isobaric fragments, iodine and n ... [Phys. Chem. Chem. Phys. 12, 7988 ] published .
Observation and control of coherent torsional dynamics in a quinquethiophene molecule
Giovanni Cirmi, Daniele Brida, Alessio Gambetta, Manuel Piacenza, Fabio Della Sala et al.
By applying femtosecond pumpprobe spectroscopy to a substituted quinquethiophene molecule in solution, we observe in the time domain the coherent torsional dynamics that drives planarization of the excited state. Our interpretation is based on numerical modeling of the ground and excited state poten ... [Phys. Chem. Chem. Phys. 12, 7917 ] published .
Spectroscopic study of the authentic emitter of AMPPD chemiluminescence in alkaline aqueous solution
Langping Tu, Yu Wang, Yifei Yang, Bert H. Bakker, Xianggui Kong et al.
To design more effective CIEEL (chemically initiated electron exchange luminescence) systems demands a complete picture of the dynamics of the chemiluminescence, which is often a challenge. In this work, photoluminescence of the methyl m-oxybenzoate anion the authentic emitter of AMPPD (3-[2-spiroa ... [Phys. Chem. Chem. Phys. 12, 6789 (2010)] published Fri Jul 2, 2010.
Exciton dynamics in photosynthetic complexes: excitation by coherent and incoherent light
Tomas ManCal and Leonas Valkunas
In this paper, we consider the dynamics of a molecular system subjected to external pumping by a light source. Within a completely quantum mechanical treatment, we derive a general formula, which enables us to assess the effects of different light properties on the photo-induced dynamics of excitati ... [New J. Phys. 12, 065044 (2010)] published Thu Jul 1, 2010.
Dynamics of electronic dephasing in the FennaMatthewsOlson complex
Dugan Hayes, Gitt Panitchayangkoon, Kelly Fransted, Justin Caram, Jianzhong Wen et al.
Electronic coherence has been shown to persist in the FennaMatthewsOlson (FMO) antenna complex from green sulfur bacteria at 77 K for at least 660 fs, several times longer than the typical lifetime of a coherence in a dynamic environment at this temperature. Such long-lived coherence was proposed to ... [New J. Phys. 12, 065042 (2010)] published Thu Jul 1, 2010.
Limits of quantum speedup in photosynthetic light harvesting
Stephan Hoyer, Mohan Sarovar, and K Birgitta Whaley
It has been suggested that excitation transport in photosynthetic light-harvesting complexes features speedups analogous to those found in quantum algorithms. Here we compare the dynamics in these light-harvesting systems to the dynamics of quantum walks, in order to elucidate the limits of such qua ... [New J. Phys. 12, 065041 (2010)] published Thu Jul 1, 2010.
Intrinsic lifetimes of the Soret bands of the free-base tetraphenylporphine (HTPP) and Cu(ii)TPP in the condensed phase
Ki Young Yeon, Dahyi Jeong, and Sang Kyu Kim
Soret band lifetimes of the free-base tetraphenylporphine (HTPP) and Cu(ii) tetraphenylporphine (CuTPP) at 408 nm have been directly measured with femtosecond (fs) resolution using the fluorescence-upconversion technique for the first time, giving tau = 68 15 and 63 15 fs, respectively, in benzene ... [Chem. Commun. 46, 5572 (2010)] published Mon Jul 26, 2010.
Fiber-optic multiphoton flow cytometry in whole blood and in vivo
Yu-Chung Chang, Jing Yong Ye, Thommey P. Thomas, Zhengyi Cao, Alina Kotlyar et al.
Circulating tumor cells in the bloodstream are sensitive indicators for metastasis and disease prognosis. Circulating cells have usually been monitored via extraction from blood, and more recently in vivo using free-space optics; however, long-term intravital monitoring of rare circulating cells rem ... [J. Biomed. Opt. 15, 047004 (2010)] published Mon Jul 26, 2010.
Combined multiphoton imaging and automated functional enucleation of porcine oocytes using femtosecond laser pulses
Kai Kuetemeyer, Andrea Lucas-Hahn, Bjoern Petersen, Erika Lemme, Petra Hassel et al.
Since the birth of Dolly as the first mammal cloned from a differentiated cell, somatic cell cloning has been successful in several mammalian species, albeit at low success rates. The highly invasive mechanical enucleation step of a cloning protocol requires sophisticated, expensive equipment and co ... [J. Biomed. Opt. 15, 046006 (2010)] published Wed Jul 21, 2010.
A computational study of ultrafast acid dissociation and acid-base neutralization reactions. I. The model
Patrick Maurer, Vibin Thomas, Ugo Rivard, and Radu Iftimie
Ultrafast, time-resolved investigations of acid-base neutralization reactions have recently been performed using systems containing the photoacid 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS) and various Bronsted bases. Two conflicting neutralization mechanisms have been formulated by ... [J. Chem. Phys. 133, 044108 (2010)] published Fri Jul 23, 2010.
Infrared signatures of the peptide dynamical transition: A molecular dynamics simulation study
Maja Kobus, Phuong H. Nguyen, and Gerhard Stock
Recent two-dimensional infrared (2D-IR) experiments on a short peptide 3-helix in chloroform solvent [E. H. G. Backus et al., J. Phys. Chem. B 113, 13405 (2009)] revealed an intriguing temperature dependence of the homogeneous line width, which was interpreted in terms of a dynamical transition of t ... [J. Chem. Phys. 133, 034512 (2010)] published Tue Jul 20, 2010.
Toward the origin of exciton electronic structure in phycobiliproteins
Jordan M. Womick, Stephen A. Miller, and Andrew M. Moran
Femtosecond laser spectroscopies are used to examine the electronic structures of two proteins found in the phycobilisome antenna of cyanobacteria, allophycocyanin (APC) and C-phycocyanin (CPC). The wave function composition involving the pairs of phycocyanobilin pigments (i.e., dimers) found in bot ... [J. Chem. Phys. 133, 024507 (2010)] published Wed Jul 14, 2010.
Anharmonicity and mode-mode coupling effects analyzed by four-wave-mixing photon-echo spectroscopy
K. K. Liang and A. A. Villaeys
The present work is devoted to the description of a nonperturbative treatment of anharmonic effect and mode-mode coupling taking place in molecular vibrational systems. The information is obtained from the four-wave-mixing signal detected in the usual photon-echo phase-matched direction, termed 4WM ... [Phys. Rev. A 82, 013423 ] published .
Phototransfection of mammalian cells using femtosecond laser pulses: optimization and applicability to stem cell differentiation
Patience Mthunzi, Kishan Dholakia, and Frank Gunn-Moore
Recently, femtosecond laser pulses have been utilized for the targeted introduction of genetic matter into mammalian cells. This rapidly expanding and developing novel optical technique using a tightly focused laser light beam is called phototransfection. Extending previous studies [Stevenson et al. ... [J. Biomed. Opt. 15, 041507 (2010)] published Tue Jul 6, 2010.
Photoacoustic lifetime imaging of dissolved oxygen using methylene blue
Shai Ashkenazi
Measuring distribution of dissolved oxygen in biological tissue is of prime interest for cancer diagnosis, prognosis, and therapy optimization. Tumor hypoxia indicates poor prognosis and resistance to radiotherapy. Despite its major clinical significance, no current imaging modality provides direct ... [J. Biomed. Opt. 15, 040501 (2010)] published Wed Jul 21, 2010.
Indirect activation of porphyrin by semiconductor quantum dots with two-photon excitation
Yanan Wen, Yuqiang Liu, Yanqiang Yang, Limin An, Weisi Song et al.
Steady-state and nanosecond time-resolved spectroscopies are performed to investigate the interaction between CdSe quantum dots (QDs) and mesotetraphenylporphyrin (TPP) photosensitizers under two-photon excitation with 800-nm femtosecond laser pulses. The luminescent intensity and lifetime of the QD ... [J. Micro/Nanolith. MEMS MOEMS 9, 031003 (2010)] published Fri Jul 2, 2010.
Exciton coherence length fluctuations in chromophore aggregates probed by multidimensional optical spectroscopy
Frantisek Sanda, Vaclav Perlik, and Shaul Mukamel
The coherent third order optical response of molecular aggregates with fluctuating frequencies, couplings, and transition dipole moments is studied. We derived stochastic nonlinear exciton equations (SNEEs) by combining the quasiparticle picture of excitons with the path integral over stochastic bat ... [J. Chem. Phys. 133, 014102 (2010)] published Fri Jul 2, 2010.
Metrology of Wide Field of View Nano-Thickness Foils' Homogeneity by Conventional and Phase Contrast Soft X-ray Imaging
Anatoly Faenov, Tatiana Pikuz, Yuji Fukuda, Masaki Kando, Hideyuki Kotaki et al.
A tabletop ultra-bright, debris-free femtosecond-laser-driven cluster-based plasma soft X-ray source, which emits more than $10^{12}$ photons/(sr$\cdot$pulse) in the spectral range 110 nm within a $4\pi$ sr solid angle was developed. Using such source in combination with a high dynamic range LiF ... [Jpn. J. Appl. Phys. 49, 06GK03 (2010)] published Thu Jul 1, 2010.
Direct frequency comb synthesis with arbitrary offset and shot-noise-limited phase noise
Sebastian Koke, Christian Grebing, Harald Frei, Alexandria Anderson, Andreas Assion et al.
Carrier-envelope phase stabilization has opened an avenue towards achieving frequency metrology with unprecedented precision and optical pulse generation on the previously inaccessible attosecond timescale. Recently, sub-100-as pulse generation has been demonstrated, approaching the timescale of the ... [Nat. Photonics 4, 462 (2010)] published Tue Jul 6, 2010.
Control of the high-order harmonics cutoff and attosecond pulse generation through the combination of a chirped fundamental laser and a subharmonic laser field
Jie Wu, Gang-Tai Zhang, Chang-Long Xia, and Xue-Shen Liu
We propose a method to generate an isolated attosecond (as) pulse in combination with a chirped fundamental laser field (5 fs, 800 nm) and a subharmonic laser field (12 fs, 1600 nm). It is shown that, for the case of the chirped parameter beta=0.25, not only is the efficiency of the extended harmoni ... [Phys. Rev. A 82, 013411 ] published .
Ultrafast Spatiotemporal Dynamics of Terahertz Generation by Ionizing Two-Color Femtosecond Pulses in Gases
I. Babushkin, W. Kuehn, C. Kohler, S. Skupin, L. Berge et al.
We present a combined theoretical and experimental study of spatiotemporal propagation effects in terahertz (THz) generation in gases using two-color ionizing laser pulses. The observed strong broadening of the THz spectra with increasing gas pressure reveals the prominent role of spatiotemporal res ... [Phys. Rev. Lett. 105, 053903 ] published .
InGaN/GaN self-organized quantum dot green light emitting diodes with reduced efficiency droop
Meng Zhang, Pallab Bhattacharya, and Wei Guo
High density (25 x 10 cm) self-organized InGaN/GaN quantum dots were grown by plasma-assisted molecular beam epitaxy. Room temperature photoluminescence shows that the quantum dots have strong emission ranging from 430 to 524 nm. The internal quantum efficiency of dots emitting at 500 nm was determ ... [Appl. Phys. Lett. 97, 011103 (2010)] published Wed Jul 7, 2010.
Short-wavelength soft-x-ray laser pumped in double-pulse single-beam non-normal incidence
D. Zimmer, D. Ros, O. Guilbaud, J. Habib, S. Kazamias et al.
We demonstrated a 7.36 nm Ni-like samarium soft-x-ray laser, pumped by 36 J of a neodymium:glass chirped-pulse amplification laser. Double-pulse single-beam non-normal-incidence pumping was applied for efficient soft-x-ray laser generation. In this case, the applied technique included a single-optic ... [Phys. Rev. A 82, 013803 ] published .
A 113 fs fiber laser operating at 1.56 [mu]m using a cascadable film-type saturable absorber with P3HT-incorporated single-wall carbon nanotubes coated on polyamide
Fumio Shohda, Masataka Nakazawa, Junji Mata, and Jun Tsukamoto
We successfully fabricated a cascadable film-type single-wall carbon nanotube (SWNT) saturable absorber coated on aromatic polyamide film, in which the saturable absorption effect can be controlled with the number of films. A conductive polymer P3HT (poly-3-hexylthiophene) was adopted to obtain a un ... [Opt. Express 18, 9712 (2010)] published Wed Jul 7, 2010.
131 fs, 33 MHz all-fiber soliton laser at 1.07 [mu]m with a film-type SWNT saturable absorber coated on polyimide
Fumio Shohda, Yuichiro Hori, Masataka Nakazawa, Junji Mata, and Jun Tsukamoto
We present a 1.07 [mu]m all-fiber femtosecond soliton laser employing a film-type saturable absorber with a P3HT (poly-3-hexylthiophene) incorporated SWNT coated on polyimide film. We optimized the laser cavity as a dispersion-managed soliton laser with photonic crystal fiber (PCF) as an anomalous d ... [Opt. Express 18, 11223 (2010)] published Wed Jul 7, 2010.
Fiber-comb-stabilized light source at 556 nm for magneto-optical trapping of ytterbium
Masami Yasuda, Takuya Kohno, Hajime Inaba, Yoshiaki Nakajima, Kazumoto Hosaka et al.
A frequency-stabilized light source emitting at 556 nm is realized by frequency doubling a 1112 nm laser, which is phase locked to a fiber-based optical frequency comb. The 1112 nm laser is either an ytterbium (Yb)-doped distributed feedback fiber laser or a master-slave laser system that uses an ex ... [J. Opt. Soc. Am. B 27, 1388 (2010)] published Thu Jul 15, 2010.
Optically induced fast wavelength modulation in a quantum cascade laser
Gang Chen, Rainer Martini, Seong-wook Park, Clyde G. Bethea, I.-Chun A. Chen et al.
An optically induced fast wavelength shift is demonstrated in a standard middle infrared (MIR) quantum cascade laser (QCL) by illuminating the front facet with a femtosecond (fs) near infrared (NIR) laser, allowing fast optical frequency modulation (FM) for free space optical communication (FSOC) an ... [Appl. Phys. Lett. 97, 011102 (2010)] published Wed Jul 7, 2010.
Kilohertz dye laser system for high resolution laser spectroscopy
J. H. Gurian, H. Maeda, and T. F. Gallagher
We have electro-optically sliced the output light of a commercial Coherent Evolution Nd:YLF laser to pump a kilohertz repetition rate nanosecond dye laser system. Simple and highly adjustable, this laser system can easily be used for initial state preparation for ultrafast systems as well as high re ... [Rev. Sci. Instrum. 81, 073111 (2010)] published Wed Jul 28, 2010.
100 W peak-power 1 GHz repetition picoseconds optical pulse generation using blue-violet GaInN diode laser mode-locked oscillator and optical amplifier
Rintaro Koda, Tomoyuki Oki, Takao Miyajima, Hideki Watanabe, Masaru Kuramoto et al.
We have generated single-transverse-mode optical pulses with 100 W peak power and 3 ps duration at 1 GHz repetition from a blue-violet GaInN mode-locked laser diode (MLLD) and a semiconductor optical amplifier (SOA) without the use of any pulse compression. The generation of clean optical pulses wit ... [Appl. Phys. Lett. 97, 021101 (2010)] published Mon Jul 12, 2010.
Design of high-energy terahertz sources based on optical rectification
J. A. Fulop, L. Palfalvi, G. Almasi, and J. Hebling
Detailed analysis of the tilted-pulse-front pumping scheme used for ultrashort THz pulse generation by optical rectification of femtosecond laser pulses is presented. It is shown that imaging errors in a pulse-front-tilting setup consisting of a grating and a lens can lead to a THz ... [Opt. Express 18, 12311 (2010)] published Wed Jul 7, 2010.

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Brain exercises delay mental decline
Fri, 03 Sep 2010 17:25:00 +1000 - New research suggests exercising your brain can keep you sharper for longer into old age, but when the symptoms of dementia finally settle in, the decline happens faster.
God did not create universe: Hawking
Fri, 03 Sep 2010 10:11:00 +1000 - God no longer has any place in theories on the creation of the universe due to a series of developments in physics, according to a new book by Stephen Hawking.
Oceans on brink of mass extinction: study
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Dying star in hot water
Thu, 02 Sep 2010 16:50:00 +1000 - Astronomers think light from distant stars may be forming water on a dying red giant twice the mass and 700 times the size of our Sun.
Females more prone to football knee injury
Thu, 02 Sep 2010 10:47:00 +1000 - 'Kicking like a girl' is a real phenomenon and may explain why females are more likely to suffer knee injuries in sports such as football, say US researcher.
Lack of sleep ups mental illness risk
Wed, 01 Sep 2010 15:30:00 +1000 - New research suggests young people getting less than five hours sleep per night are tripling their chances of developing a mental illness.
Tiny creatures reveal ancient sea levels
Wed, 01 Sep 2010 12:05:00 +1000 - Tiny marine creatures found on the seabed on opposite sides of West Antarctic give a strong hint of the effects of sea level rise, say scientists.
Communal feasts date back 12,000 years
Tue, 31 Aug 2010 14:15:00 +1000 - Community feasts were probably a common occurrence among early humans, possibly predating the advent of agriculture, according to a new study.
Virus-built batteries to provide power
Tue, 31 Aug 2010 11:00:00 +1000 - Batteries built by viruses could soon power your mobile phone or be sprayed onto uniforms as wearable power sources.
Review calls for UN climate shake-up
Tue, 31 Aug 2010 02:20:00 +1000 - A shake-up has been recommended for the UN climate panel, a body which came under fire recently in the so-called 'Climategate' scandal.
Genome of the apple laid bare
Mon, 30 Aug 2010 10:29:00 +1000 - One of the world's most popular fruits, the apple, has been genetically sequenced, an exploit that could lead to crisper, juicier and more flavoursome harvests, says scientists.
DNA snip may decode cause of migraine
Mon, 30 Aug 2010 03:00:00 +1000 - Our understanding of what causes migraines has moved a step closer with the publication of a large European study.
Solar max claims 'overstated': expert
Fri, 27 Aug 2010 16:30:00 +1000 - Australia's leading body responsible for monitoring space weather has dismissed claims that a massive solar storm could "wipe out the Earth's entire power grid".
Diamonds are a supercomputer's best friend
Fri, 27 Aug 2010 12:48:00 +1000 - Scientists in California have used commercially available technology to create diamonds with tiny, nitrogen-filled holes, which could be the key to the next generation of supercomputers.
YouTube clips pushing tobacco: study
Fri, 27 Aug 2010 11:13:00 +1000 - YouTube has become an arena for encouraging smoking among young people, hosting videos that link cigarettes with celebrities, music, sporting success and cartoons, according to medical researchers.

Select a Tag for more information.

PHYSorg.com: Technology News

PhysOrg.com provides the latest news on technology, software, computer science, internet, semiconductor, telecom and science technology.

Texas opens inquiry into Google search results
Fri, 03 Sep 2010 18:50:02 EST - (AP) -- Google says Texas Attorney General Greg Abbott is investigating whether its Web search rankings are fair.
Google to pay 8.5 million dollars to settle Buzz case
Fri, 03 Sep 2010 18:50:01 EST - Google has agreed to pay 8.5 million dollars (US) to settle a privacy lawsuit over a Buzz social networking tool added to free email service Gmail in February, according to court documents.
Interview: Wikipedia founder bullish on news
Fri, 03 Sep 2010 18:30:01 EST - (AP) -- Wikipedia founder Jimmy Wales believes relief may be in sight for the beleaguered news media industry.
Texting on the rise among US adults: Pew survey
Fri, 03 Sep 2010 18:20:25 EST - More American adults are texting but they are not tapping out nearly as many messages per day on their cellphones as teenagers, according to a new survey from the Pew Research Center.
German court rules against YouTube over copyright
Fri, 03 Sep 2010 18:17:07 EST - (AP) -- A German court ruled Friday that Google Inc.'s subsidiary YouTube LLC must pay compensation after users uploaded several videos of performances by singer Sarah Brightman in violation of copyright laws.
Google updates privacy policy
Fri, 03 Sep 2010 15:10:01 EST - Google updated its privacy policy on Friday, a day after a video cartoon featuring the Internet firm's chief giving away ice cream to snoop on children aired on a giant screen in Times Square.
YouTube to turn profit this year: NY Times
Fri, 03 Sep 2010 12:35:48 EST - Google-owned videosharing website YouTube is expected to turn a profit this year on revenue of 450 million dollars, The New York Times reported Friday.
GPS keeps track of school bus riders
Fri, 03 Sep 2010 11:50:03 EST - Josh Case climbed aboard the yellow school bus Tuesday, lifting his backpack to scan an ID card that had been assigned to him on his first day of kindergarten.
Taking the 'search' out of search and rescue
Fri, 03 Sep 2010 11:50:01 EST - Their emergencies happened hundreds, if not thousands, of miles from one another, but the captain whose vessel had become disabled near Kamalino, Hawaii, the pilot who crashed onto the Knik Glacier near Anchorage, Alaska, and the hiker who suffered a compound fracture while hiking near Merritt, Washington, all share a common experience: They were plucked to safety in the weeks leading up to the Labor Day weekend due to NASA technology.
Dubai police chief calls BlackBerry a spy tool
Fri, 03 Sep 2010 11:30:01 EST - (AP) -- Worries about spying by the U.S. and Israel spurred plans to sharply limit BlackBerry services in the United Arab Emirates, Dubai's police chief said in comments that suggest a tough line in talks with the smart phone maker.
Recording companies eager for Google to launch music service
Fri, 03 Sep 2010 11:20:01 EST - Google Inc., which is developing a digital music service, is winning over record companies that are hoping the technology company can loosen Apple Inc.'s grip on the digital music market.
Twitter tops 145 million registered users: CEO
Fri, 03 Sep 2010 10:59:44 EST - Twitter has over 145 million registered users and more people are using mobile devices to access the microblogging service, according to co-founder Evan Williams.
Review: mTrip iPhone app uses augmented reality
Fri, 03 Sep 2010 10:57:15 EST - (AP) -- The new iPhone application mTrip is a travel guide and then some: It uses the latest in smart phone technology to make it easier to stay on track in a foreign locale.
Time Warner Cable gets ESPN3.com in new deal
Fri, 03 Sep 2010 09:27:55 EST - (AP) -- Time Warner Cable Inc. customers will finally get access to the sports website ESPN3.com, even if they are not subscribers of the company's Internet service, according to a long-term deal with The Walt Disney Co. announced Thursday.
HP finds partner to build memristors into chips
Fri, 03 Sep 2010 07:50:01 EST - Hewlett-Packard Co. has found an ally to take a breakthrough research project of HP's and build the technology into computer chips.
Video lambasting Google on privacy hits Times Square
Fri, 03 Sep 2010 04:55:10 EST - A video cartoon featuring Google's chief giving away ice cream to snoop on children aired on a giant screen in Times Square as a privacy group continued to hound the Internet giant.
Dell's enterprise challenge remains after 3Par
Thu, 02 Sep 2010 19:40:03 EST - (AP) -- Dell Inc. doesn't have to start over in its quest to become a significant purveyor of technology for businesses after losing a multibillion dollar bidding contest for an obscure data-storage maker.
Facebook's new security feature: remote logouts
Thu, 02 Sep 2010 17:50:08 EST - (AP) -- Facebook is rolling out a new security feature that lets users log out of their accounts remotely from another computer.
Tire-pressure monitors vulnerable, researchers say
Thu, 02 Sep 2010 17:00:01 EST - (PhysOrg.com) -- Wireless tire pressure monitoring systems designed to alert drivers to problems with low tire pressure can be intercepted or forged, causing possible security or privacy threats, according to research at the University of South Carolina and Rutgers University.
Cisco buying smart grid specialty firm Arch Rock
Thu, 02 Sep 2010 16:24:31 EST - Computer networking powerhouse Cisco on Thursday announced it intends to buy smart grid specialty firm Arch Rock.
Verizon to sell smart phones for prepaid service
Thu, 02 Sep 2010 15:50:03 EST - (AP) -- Verizon Wireless on Thursday announced it's opening up access to smart phones for customers who prepay for service, such as people with poor credit and those who don't want to be tied down by long-term contracts.
Online education expands, but is it effective?
Thu, 02 Sep 2010 15:50:01 EST - Clinton Parker, a senior at Julian High School, worked quietly at his computer in August as the clicks of mice from more than a dozen students punctured the air of an otherwise silent computer lab.
Elpida and Spansion develop 4-Gigabit NAND flash memory
Thu, 02 Sep 2010 15:09:46 EST - Elpida Memory and Spansion today announced they have created the industry's first charge-trapping 1.8 V, 4-gigabit SLC (Single Level Cell) NAND Flash memory. This NAND memory, based on Spansion's MirrorBit charge-trapping technology, is being produced at Elpida's Hiroshima factory. The advanced technical expertise and strong cooperation of the two companies has made it possible to develop and manufacture the world's first charge-trapping NAND Flash memory.
Chrome update marks Web browser's second birthday
Thu, 02 Sep 2010 14:28:16 EST - Google released an improved version of Chrome on Thursday as the Internet titan's Web browser turned two years old.
Twitter launches iPad application
Thu, 02 Sep 2010 13:21:11 EST - Hot microblogging service Twitter launched an application for the Apple iPad on Thursday to rave reviews from technology blogs.
Melding Wi-Fi with digital TV 'white space'
Thu, 02 Sep 2010 12:52:09 EST - Rice University researchers have won a $1.8 million federal grant for one of the nation's first, real-world tests of wireless communications technology that uses a broad spectral range -- including dormant broadcast television channels -- to deliver free, high-speed broadband Internet service. The five-year project calls for Rice and Houston nonprofit Technology For All (TFA) to add "white space" technology to the wide spectrum Wi-Fi network they jointly operate in Houston's working-class East End neighborhood.
Google, Skype targeted in India security crackdown
Thu, 02 Sep 2010 11:40:01 EST - (AP) -- India has widened its security crackdown, asking all companies that provide encrypted communications - not just BlackBerry-maker Research In Motion - to install servers in the country to make it easier for the government to obtain users' data. That would likely affect digital giants like Google and Skype.
Interview: UN telecoms chief urges data sharing
Thu, 02 Sep 2010 11:24:08 EST - (AP) -- BlackBerry's Canadian manufacturer should give law enforcement agencies around the world access to its customer data, the U.N. technology chief said, adding that governments have legitimate security concerns that should not be ignored.
Dell cedes data-storage maker 3Par to HP
Thu, 02 Sep 2010 10:30:57 EST - (AP) -- Dell Inc. is walking away from a bidding contest with rival Hewlett-Packard Co. for data-storage maker 3Par Inc.
New AOL search deal with Google includes mobile
Thu, 02 Sep 2010 10:00:01 EST - (AP) -- Google Inc. will continue to provide the search results on AOL Inc.'s websites under a new, five-year deal the companies signed this week.

PHYSorg.com: Hi Tech & Innovation News

PhysOrg.com provides the latest news on hi-tech, innovation and new inventions technology, computer news and information

GPS keeps track of school bus riders
Fri, 03 Sep 2010 11:50:03 EST - Josh Case climbed aboard the yellow school bus Tuesday, lifting his backpack to scan an ID card that had been assigned to him on his first day of kindergarten.
Video chat expands possibilities for face-to-face services
Thu, 02 Sep 2010 08:40:01 EST - You once had to leave home to see a psychiatrist for therapy, a music teacher for guitar lessons or a makeup artist for face-to-face consultations. Now they can come to you, virtually, through video chat.
Adaptive headlamp system introduced
Thu, 02 Sep 2010 06:50:01 EST - (PhysOrg.com) -- The independent industrial group Valeo, which is headquartered in France, has introduced a "BeamAtic" adaptive headlight system that enables drivers to keep their lights on high beam without dazzling other drivers.
Japan resort draws men with virtual girlfriends
Mon, 30 Aug 2010 04:10:01 EST - Long a favourite of lovers and honeymooners, a Japanese beach town with fading sparkle has found a new tourism niche in the wired age by drawing young men and their virtual girlfriends.
Sony working on 3-D TVs that don't need glasses
Thu, 26 Aug 2010 08:07:50 EST - (AP) -- Sony Corp. is working on 3-D televisions that don't need special glasses, joining a race with rival Toshiba Corp., but sees cost and technological hurdles to overcome before they can go on sale.
Japan develops 'touchable' 3D TV technology
Thu, 26 Aug 2010 06:02:18 EST - A Japanese research team said Thursday it had developed the world's first 3D television system that allows users to touch, pinch or poke images floating in front of them.
Thought-controlled computers on the way: Intel
Wed, 25 Aug 2010 08:00:10 EST - (PhysOrg.com) -- Computers controlled by the mind are going a step further with Intel's development of mind-controlled computers. Existing computers operated by brain power require the user to mentally move a cursor on the screen, but the new computers will be designed to directly read the words thought by the user.
Japan high-tech toilet makers flush with success
Wed, 25 Aug 2010 05:37:47 EST - In Japan, the global leader in high-tech toilet design, the latest restroom marvel should come with a health warning for hypochondriacs -- it doubles as a medical lab that can really spoil your day.
'Super bus' could cure Beijing traffic woes
Tue, 24 Aug 2010 04:42:01 EST - China's capital Beijing, recently named along with Mexico City as having the worst traffic jams in the world, is looking for solutions. One could be the elevated "super bus".
Toshiba makes a breakthrough in hard-drive capacity
Mon, 23 Aug 2010 12:37:39 EST - (PhysOrg.com) -- Last Wednesday Toshiba made an announcement at the Magnetic Recording Conference in San Diego that they have made a breakthrough in their research of bit-patterned media that would result in enormous storage improvements for future hard drives.
University of Washington testing sign language video phones
Fri, 20 Aug 2010 11:40:02 EST - A new tool for communicating using American Sign Language over video phones is being field tested in the Seattle this summer by University of Washington researchers, who plan to expand the program this winter.
Solar-powered toothbrush doesn't require toothpaste
Fri, 20 Aug 2010 05:58:11 EST - (PhysOrg.com) -- Researchers have designed a toothbrush that cleans teeth by creating a solar-powered chemical reaction in the mouth, doing away with the need for toothpaste.
Gaming giants bet on 3D for next big boost
Wed, 18 Aug 2010 12:20:46 EST - The global gaming industry is jumping on Hollywood's 3D bandwagon but the bet is risky as consumers appear reluctant to shell out for the necessary screens and glasses, insiders said Wednesday.
Robotic arm simulates driving a Ferrari (w/ Video)
Mon, 16 Aug 2010 04:50:01 EST - Engineers have turned a robotic arm into a `Ferrari simulator,` enabling users to feel what it`s like to experience high-speed driving while controlling the car in a video game. As shown in the video below, players sit in the robotic arm positioned about two meters off the ground, and the arm twists and turns to simulate the car`s motion.
Innovative approach to teaching forensics helps students track and solve crimes
Fri, 13 Aug 2010 13:40:05 EST - A novel approach to teaching forensics at the University of Toronto Mississauga`s Forensic Anthropology Field School is using global positioning systems (GPS) and geographical information systems (GIS) to examine complex crime scenes.
Europe ready to launch 3-D TV outperforming the competition
Fri, 13 Aug 2010 10:40:57 EST - No one forgets their first 3D film experience. Some people first experienced the illusion of an extra dimension wearing red and green glasses inside an attraction at a theme park. They may have watched short films simulating dizzying rides on rollercoasters or high-speed skiing. Others may have been wowed for the first time by the 3D version of James Cameron's film Avatar.
Video quality less important when you're enjoying what you're watching
Thu, 12 Aug 2010 11:31:05 EST - Research from Rice University's Department of Psychology finds that if you like what you're watching, you're less likely to notice the difference in video quality of the TV show, Internet video or mobile movie clip.
Person-to-person payments catch on with banks
Wed, 04 Aug 2010 18:30:02 EST - You're out for dinner with a friend and the bill arrives. But, oops, you're short on cash and can't pay up.
Japan mobile phone makers to roll out 'augmented reality'
Sun, 01 Aug 2010 14:10:03 EST - The "Terminator" had it, US fighter pilots use it and it's the next hot feature on Japanese smartphones -- "augmented reality" which peppers the world around you with useful bits of information.
Soaring e-book sales speak volumes
Sun, 01 Aug 2010 14:00:01 EST - After years of lurking in the literary wilderness, the e-book market has exploded with online retailer Amazon.com's digital volumes recently overtaking sales of their hardcover counterparts.
Singapore Airlines to introduce electronic magazines
Fri, 30 Jul 2010 08:50:01 EST - Singapore Airlines said Friday it is to introduce an electronic version of its inflight magazines as part of its plans for paperless planes.
Microsoft Street Slide threatens to eclipse street view rivals (w/ Video)
Thu, 29 Jul 2010 07:50:01 EST - (PhysOrg.com) -- Microsoft has unveiled "Street Slide," which gives viewers 360-degree multi-perspective panoramas ("bubbles") of a city streetscape. The system should rival Google's Street View and Bing Maps' Streetside.
Nissan to offer breathable Vitamin C in new cars
Wed, 28 Jul 2010 05:32:59 EST - In a riposte to those who think a reliance on cars is unhealthy, new Nissan models will feature air conditioners that pump breathable vitamin C and stress-reducing seats, the firm said Wednesday.
S.Korea kids to carry GPS beepers against sex crime
Wed, 28 Jul 2010 02:16:58 EST - South Korea, shaken by several brutal sex crimes against minors, will supply children with GPS-embedded beepers to warn police of dangers and activate surveillance cameras, officials said Wednesday.
Raytheon unveils Scorpion helmet technology
Fri, 23 Jul 2010 12:57:42 EST - (AP) -- As the desert landscape unfolds ahead, the jet fighter pilot glances to his right. Spotting an enemy target, a sensor attached to his helmet relays the information straight back to his flight controls, allowing him to fire immediately without turning his aircraft.
Introducing Cornucopia, the food printer
Fri, 23 Jul 2010 07:00:01 EST - (PhysOrg.com) -- US scientists have introduced a concept design of the "Cornucopia" or Digital Fabricator, a "personal food factory" able to print food from specified ingredients, with no waste at the point of cooking.
The future of reading
Wed, 21 Jul 2010 20:20:01 EST - Emma Teitgen, 12, thought the chemistry book her teacher recommended would make perfect bedside reading. Perfect because it might help her fall asleep.
New wave of banking: Check deposit via smart-phone photo
Wed, 21 Jul 2010 18:15:10 EST - Customers at Chase Bank have a new way to deposit checks: Just snap, snap and tap. Chase has introduced an iPhone application allowing consumers to deposit checks with the camera-enabled smart device, which means no more trips to a local bank branch or ATM or hassling with deposit slips.
Italy to China in driverless vehicles
Tue, 20 Jul 2010 09:33:42 EST - (AP) -- It's a modern-day version of Marco Polo's journey halfway around the world - but is anyone at the controls?
Spanish channel announces 'world's first 3-D TV series'
Mon, 19 Jul 2010 16:50:01 EST - Spanish TV firm Antena 3 will shoot an entire season of one of its television series entirely in 3-D in what it said would be a world first.

Techopolis

Technology Trends, Cool Gadgets and Gizmos

Digital Vinyl Tracks - The Lenco L-71 Turntable Converts Oldies into MP3s
2010-09-03T21:31:02+00:00 - The Lenco L-71 Turntable brings the 70s into the 21st century with its groovy reading and encoding capabilities. The product is complete with a belt drive turntable that can copy your old favorite bands…
Saucer-Like Sound Systems - The Korean UFO Bluetooth Speaker is Out of this World
2010-09-03T20:49:01+00:00 - These Korean UFO Bluetooth Speakers resemble flying saucers, perfect for those obsessed with outer space. Capable of being both a sound system and an mp3 player, these Korean UFO Bluetooth speakers also…
Ocular Text Lenses - BabelFisk Glasses Turns Speech to Text Before Your Eyes
2010-09-03T20:22:02+00:00 - Mads Hindhedes’ BabelFisk glasses takes verbal speech and translates it into readable text right before your very eyes. With speech recognition software combined with hearing aid algorithms, the result…
Urbantastic Phone Covers - Stussy and Zozotown Pair Up to Design Interesting iPhone Cases
2010-09-03T17:38:01+00:00 - Stussy and Zozotown are collaborating to create a line of skate fashion-inspired cases for the iPhone 4 to kick off Zozotown's New Design Project Volume 2. The cases don graffiti art straight from…
Baby-Monitoring Sleepwear - Easily Check on Your Baby With the Exmobaby Biosensor Pajamas
2010-09-03T16:52:01+00:00 - If you are a parent who knows the hassle of baby monitors, you may appreciate these featured Exmobaby Biosensor Pajamas. These interesting Exmobaby Sensor Pajamas incorporate a baby monitor within the…
Intense Illuminating Accessories - Oleh Lighting Concepts Brighten Bodies and Bus Stops
2010-09-03T16:30:02+00:00 - Konica Minolta and Agent have collaborated to launch OLEH Lighting Concepts as an exploration of new OLED technology applications. The team has come up with both Strip Light and Wearable concepts. This…
Computer Couch Cushions - The Plush iMac is a Must-Have for Apple Fanboys and Girls
2010-09-03T16:20:01+00:00 - If you love Apple and their products as much as you say you do, then you will welcome the Plush iMac into your house with arms wide open. This pillow was designed by Kerry Hughes to look exactly like an…
Social Media Sustenance - The Meet Eater Plant Survives on Social Interactions With Users
2010-09-03T14:47:02+00:00 - The first living organism beyond the occasional teenager to rely solely on social media for survival is the Meet Eater plant. That plant was a social experiment by a student at the University of Queensland…
Audio-Recording Stationary - The Rec & Play Pen by Yuri Suzuki and Oscar Diaz is Extraordinary
2010-09-03T13:57:01+00:00 - The Rec & Play pen is an extraordinary hybrid writing tool. Essentially, it "combines sound, sight and physical movement," according to PSFK, creating the most practical piece of stationary you could ever…
Multi-Talented Thermoses - The GreenTek ‘Solar Mug’ Can Heat Coffee and Recharge Phones
2010-09-03T13:02:02+00:00 - The GreenTek ‘Solar Mug’ is like no mug you’ve ever encountered. Not only is the thermos equipped with a temperature control to keep your coffee at your heated preference, but cold temperatures can be…

NaviGadget

GPS Navigation Systems, GPS Tracking Devices, GPS Phones, Receivers, Reviews, and Hacks

Motorola XT806 does GPS with Android
Thu, 02 Sep 2010 08:43:21 +0000 - For China only! So don’t get too excited about these transparent-lid touch screen phones if you’re in Europe or the U.S. I wonder why only Chinese get these transparent covers. Maybe they’re notorious for putting them in their pockets with keys or something. Who knows. Anyhow one of these new models is the Motorola XT806 [...]

Brought to you by your GPS navigation site NaviGadget.

Motorola XT806 does GPS with Android

Sony Xplod navigation comes with TomTom software
Thu, 02 Sep 2010 03:34:51 +0000 - The new SonyXplod AV Navigation Systems will be coming with TomTom navigation software which is fully connected, offering LIVE services such as HD Traffic to keep you out of traffic jams and Google business address searches. Other TomTom features that are available on Sony Xplod (aka XNV-L77BT) are the IQ Routes and Map Share which [...]

Brought to you by your GPS navigation site NaviGadget.

Sony Xplod navigation comes with TomTom software

Garmin-Asus A10 out in New Zealand
Thu, 02 Sep 2010 02:40:03 +0000 - Garmin-Asus A10 is out in New Zealand; available at Telecom New Zealand. As you know Garmin-Asus A10 is an Android device with a greater focus on GPS navigation; targeting European and Asia-Pacific nations. The device will come with everything you need to utilize it it your car including an in-car mount and a car charger. [...]

Brought to you by your GPS navigation site NaviGadget.

Garmin-Asus A10 out in New Zealand

American Rydeen gPad GCOM701 comes with maps
Wed, 01 Sep 2010 10:06:37 +0000 - West coast based Rydeen just announced GCOM701, a new Android tablet device with GPS functionality. Also known as gPad, the device has a 7″ touch screen, front-facing camera, and removable memory. It will be ready in November but the price has not been announced yet. GCOM701 TFT touch panel has 800×480-pixel resolution, WiFi connectivity (802.11 [...]

Brought to you by your GPS navigation site NaviGadget.

American Rydeen gPad GCOM701 comes with maps

using Motion X GPS Drive on your iPad
Tue, 31 Aug 2010 05:24:42 +0000 - This dude has done it. It is not the most elegant way of using your iPad as a GPS navigation system but may serves as a proof of concept. Like we said he’s using Motion X GPS drive as the GPS navigation software which only costs $3 to buy but you’ll have to pay $25/year [...]

Brought to you by your GPS navigation site NaviGadget.

using Motion X GPS Drive on your iPad

ACR AquaLink View PLB with 406link
Sun, 29 Aug 2010 20:26:38 +0000 - Interested in a marine personal locator beacon? This one is ACR AquaLink View PLB and Panbo has a good review about it. Because I’m also testing the Pro version of ACR’s 406Link service, the same “All’s well” short message and location link could have been emailed and/or texted to four other recipients. Frankly, though, I [...]

Brought to you by your GPS navigation site NaviGadget.

ACR AquaLink View PLB with 406link

garmin edge 800
Sun, 29 Aug 2010 00:26:26 +0000 - Garmin just announced a new touchscreen device for cyclists called Edge 800. It provides BirdsEye Satellite Imagery, has a bigger 2.6″ display compared to older Edge models. It can track all of your performance data, on and off road and always helps you find your way back to the start. Edge 800 tracks speed, distance, [...]

Brought to you by your GPS navigation site NaviGadget.

garmin edge 800

garmin’s major recall
Fri, 27 Aug 2010 16:51:42 +0000 - You’ve probably heard this already but we’ll just go over a few of the details: Garmin is recalling 1.25 million nuvi GPS navigation systems (796K of them in the U.S.) there are issues with overheating batteries they’re blaming a third party battery supplier affected models are 200W, 250W, 260W, 7xx, and 7xxT however not all [...]

Brought to you by your GPS navigation site NaviGadget.

garmin’s major recall

bushnell backtrack point >5
Fri, 27 Aug 2010 15:42:38 +0000 - Bushnell just upgraded their “backtrack >3″ to “backtrack >5″, a whole two new locations you can track for an extra $20. It is not currently in stock; maybe that’s a good thing because our favorite GPS X GUIDER which can store up to 300 points is in stock. Bushnell backtrack point >5 has a different [...]

Brought to you by your GPS navigation site NaviGadget.

bushnell backtrack point >5

new Cobra Platinum navigation system is for truckers
Tue, 24 Aug 2010 16:41:25 +0000 - Cobra just announced a new GPS navigation system called 7750 Platinum which has a 7″ screen and is designed for professional drivers. Cobra has added some new features with this model such as the junction view with lane assist, mileage log, and hours of service, etc. Other enhancements include on the 7750 Platinum include visibility [...]

Brought to you by your GPS navigation site NaviGadget.

new Cobra Platinum navigation system is for truckers

PHYSorg.com: Physics News

Physorg.com provides the latest news on physics, materials, nanotech, science and technology. Updated Daily.

Magnetism's subatomic roots: Study of high-tech materials helps explain everyday phenomenon
Fri, 03 Sep 2010 11:58:56 EST - (PhysOrg.com) -- The modern world -- with its ubiquitous electronic devices and electrical power -- can trace its lineage directly to the discovery, less than two centuries ago, of the link between electricity and magnetism. But while engineers have harnessed electromagnetic forces on a global scale, physicists still struggle to describe the dance between electrons that creates magnetic fields.
Physicists find fractal boundaries in crystals
Fri, 03 Sep 2010 07:17:37 EST - Blacksmiths make horseshoes by heating, beating and bending iron, but what's happening to the metal's individual atoms during such a process? Cornell researchers, using computational modeling, are providing new insight into how atoms in crystals rearrange as the material is bent and shaped.
Scientists investigate how ice melts below freezing due to nanowire's pressure
Thu, 02 Sep 2010 11:19:03 EST - (PhysOrg.com) -- The many ways in which water differs from other molecules is both a scientific curiosity and an important factor in shaping the Earth. Among water's unique properties are that it expands when it freezes, it boils and freezes at higher temperatures than expected for a compound with its molecular structure, and it has the ability to absorb large amounts of heat without getting hot. In a recent study, scientists have investigated another unique phenomenon of water called regelation, which occurs when frozen water - or ice - melts under high pressures, even if the temperature is below freezing. Once the pressure is lifted, the water refreezes.
Delving into the world of the ultra-cold
Thu, 02 Sep 2010 05:34:07 EST - (PhysOrg.com) -- In Swinburne University's 'cold molecules lab', where temperatures one millionth of a degree above absolute zero are routinely achieved, researchers are making significant advances in understanding the weird and wonderful world of quantum mechanics.
Carlos '97 free kick no fluke, say French physicists
Thu, 02 Sep 2010 04:01:28 EST - Roberto Carlos' free kick goal against France in 1997's Tournoi de France is thought by many to have been the most skilful free kick goal - from 35m with a powerful curling banana trajectory - ever scored; but by others to have been an incredible fluke.
Glasperlenspiel: Scientists propose new test for gravity
Wed, 01 Sep 2010 14:30:01 EST - A new experiment proposed* by physicists at the National Institute of Standards and Technology may allow researchers to test the effects of gravity with unprecedented precision at very short distances -- a scale at which exotic new details of gravity's behavior may be detectable.
A model system for group behavior of nanomachines
Wed, 01 Sep 2010 13:42:59 EST - For the casual observer it is fascinating to watch the orderly and seemingly choreographed motion of hundreds or even thousands of fish, birds or insects. However, the formation and the manifold motion patterns of such flocks raise numerous questions fundamental to the understanding of complex systems.
New material may reveal inner workings of hi-temp superconductors
Wed, 01 Sep 2010 12:23:53 EST - Measurements taken* at the National Institute of Standards and Technology may help physicists develop a clearer understanding of high-temperature superconductors, whose behavior remains in many ways mysterious decades after their discovery. A new copper-based compound exhibits properties never before seen in a superconductor and could be a step toward solving part of the mystery.
NIST researchers create 'quantum cats' made of light
Wed, 01 Sep 2010 12:10:04 EST - Researchers at the National Institute of Standards and Technology have created "quantum cats" made of photons (particles of light), boosting prospects for manipulating light in new ways to enhance precision measurements as well as computing and communications based on quantum physics.
New study suggests researchers can now test the 'theory of everything'
Wed, 01 Sep 2010 09:45:07 EST - (PhysOrg.com) -- Researchers describe how to carry out the first experimental test of string theory in a paper published tomorrow in Physical Review Letters.
Physicists propose quantum refrigerator
Wed, 01 Sep 2010 07:10:01 EST - (PhysOrg.com) -- Scientists at the University of Bristol in the UK have proposed a refrigerator that consists of just a few quantum particles -- qubits.
IceCube neutrino observatory nears completion
Tue, 31 Aug 2010 14:19:19 EST - In December 2010, IceCube -- the world's first kilometer-scale neutrino observatory, which is located beneath the Antarctic ice -- will finally be completed after two decades of planning. In an article in the AIP's Review of Scientific Instruments, Francis Halzen, the principal investigator of the IceCube project, and his colleague Spencer Klein of Lawrence Berkeley National Laboratory provide a comprehensive description of the observatory, its instrumentation, and its scientific mission -- including its most publicized goal: finding the sources of cosmic rays.
LEDs illuminate eye for ocular disease screening
Tue, 31 Aug 2010 14:16:18 EST - A new imaging system using six different wavelengths to illuminate the interior of the eyeball (ocular fundus) may pave the way for doctors to easily screen patients for common diseases of the eye, such as age-related macular degeneration and diabetic retinopathy. The system is described in the journal Review of Scientific Instruments.
Radioactive decay rates vary with the sun's rotation: research
Tue, 31 Aug 2010 06:58:03 EST - Radioactive decay rates, thought to be unique physical constants and counted on in such fields as medicine and anthropology, may be more variable than once thought.
Probing spin liquids with a new pulsed-magnet system
Mon, 30 Aug 2010 16:57:22 EST - Entirely new experimental vistas could be opened by a device called a precursor pulsed-magnet system developed by an international team of scientists. This system can generate magnetic fields as high as 30 Tesla for synchrotron x-ray scattering experiments. The researchers recently completed the first practical work using the system at the U.S. Department of Energy`s Advanced Photon Source (APS) at Argonne National Laboratory to study magnetoelastic effects in the rare-earth pyrochlore terbium titanate (Tb2Ti2O7). Their findings were published in Physical Review Letters.
Producing isolated laser pulses in attoseconds made easier using two-color laser field
Mon, 30 Aug 2010 14:50:03 EST - Ultrafast time-resolved laser spectroscopy is a technique that uses the interaction of light with matter to study the properties of physical systems. Researchers can generate laser pulses lasting mere attoseconds -- quintillionths of seconds -- to examine the nuclear dynamics in different states of matter, including single atoms.
First direct observation of unusual magnetic structure could lead to novel electronic, magnetic memory devices
Mon, 30 Aug 2010 13:50:23 EST - In conventional ferromagnets, the individual magnetic moments of the atoms that together comprise the magnetism of the material are all aligned parallel, pointing in a common direction. In some magnets, quantum-mechanical interactions between the electrons of a material or the presence of internal electric fields, for example, mean that the magnetic arrangements are more complex.
Better light measurement through quantum cloning
Mon, 30 Aug 2010 07:30:01 EST - (PhysOrg.com) -- "One of the things we have been studying is how the world works on a really small scale," Bruno Sanguinetti, a scientist at the University of Geneva in Switzerland tells PhysOrg.com. "At the quantum level, the world can behave in ways that are far from our everyday experience. For example, information at the quantum level cannot be copied exactly." This is different, he continues, from the ease with which we can copy information in the classical regime.
Location determines social network influence, study finds
Sun, 29 Aug 2010 13:00:05 EST - A team of researchers led by Dr. Hernan Makse, professor of physics at The City College of New York (CCNY), has shed new light on the way that information and infectious diseases proliferate across complex networks. Writing in Nature Physics, they report that, contrary to conventional wisdom, persons with the most connections are not necessarily the best spreaders.
Vulnerability in commercial quantum cryptography
Sun, 29 Aug 2010 13:00:01 EST - The Norwegian University of Science and Technology (NTNU) and the University of Erlangen-Nurnberg together with the Max Planck Institute for the Science of Light in Erlangen have recently developed and tested a technique exploiting imperfections in quantum cryptography systems to implement an attack.
Prediction of intrinsic magnetism at silicon surfaces could lead to single-spin magnetoelectronics
Thu, 26 Aug 2010 12:12:42 EST - The integration of single-spin magnetoelectronics into standard silicon technology may soon be possible, if experiments confirm a new theoretical prediction by physicists at the Naval Research Laboratory and the University of Wisconsin-Madison.
Discovery could challenge established theory of the nucleus
Thu, 26 Aug 2010 07:41:58 EST - (PhysOrg.com) -- By analyzing data from experiments performed earlier this decade at the Oak Ridge Electron Linear Accelerator (ORELA), physicists have made observations that seem to conflict with the widely accepted theory of the nucleus.
Major budget cuts to slow world's biggest atom smasher: CERN (Update)
Wed, 25 Aug 2010 10:36:38 EST - European budget cuts at the world's biggest atom smasher are set to slow down its quest to unlock the deepest secrets of the universe, management and staff warned on Wednesday.
Creating light sources for nanochips
Wed, 25 Aug 2010 08:30:01 EST - (PhysOrg.com) -- "One of the most important goals in the optics community is to create and manipulate light on chip," Yinan Zhang tells PhysOrg.com. "This is especially important when it comes to improving the performance of semiconductor lasers with increasingly small device size. This device improvement, owing to recent developments in nanotechnology, will enable a high integration capacity of photonic devices in the future. This could take place in a fashion similar to what has happened to the semiconductor electronic industry."
Atmospheric pressure plasma jet from a grounded electrode
Tue, 24 Aug 2010 16:50:48 EST - Because they are portable and easy to operate at ambient temperatures, cold atmospheric pressure plasma jets (APPJs) should find innovative applications in biomedicine, materials science and fabrication industries. Research reported in the Journal of Applied Physics investigates an APPJ that extends from the ground electrode of a circuit.
Half-a-loaf method can improve magnetic memories
Tue, 24 Aug 2010 16:48:51 EST - Chinese scientists have shown that magnetic memory, logic and sensor cells can be made faster and more energy efficient by using an electric, not magnetic, field to flip the magnetization of the sensing layer only about halfway, rather than completely to the opposite direction. They describe the new cell design in the Journal of Applied Physics.
Glorious gadolinium gives flash memory a future
Tue, 24 Aug 2010 16:45:38 EST - Future flash memory could be faster and store more data without changing its basic design by using a clever nanocrystal material proposed by scientists at Taiwan's Chang Gung University, who describe a new logical element made with the rare earth material gadolinium in the journal Applied Physics Letters.
'Spintronics' breakthrough holds promise for next-generation computers
Tue, 24 Aug 2010 12:59:07 EST - Using powerful lasers, Hui Zhao, assistant professor of physics and astronomy at the University of Kansas, and graduate student Lalani Werake have discovered a new way to recognize currents of spinning electrons within a semiconductor.
LEDs promise brighter future, not necessarily greener
Tue, 24 Aug 2010 12:44:16 EST - Solid-state lighting pioneers long have held that replacing the inefficient Edison light bulb with more efficient solid-state light-emitting devices (LEDs) would lower electrical usage worldwide, not only "greenly" decreasing the need for new power plants but even permitting some to be decommissioned.
The strange case of solar flares and radioactive elements
Mon, 23 Aug 2010 15:19:46 EST - (PhysOrg.com) -- When researchers found an unusual linkage between solar flares and the inner life of radioactive elements on Earth, it touched off a scientific detective investigation that could end up protecting the lives of space-walking astronauts and maybe rewriting some of the assumptions of physics.

ScienCentral

Making Sense of Science

Hawaiian Heat
Tue, 13 Oct 2009 00:00:00 +0000 - With climate change forecasts calling for tough times in tropical climates, scientists in America’s tropical paradise of Hawaii are carefully monitoring nature for signs of change, and citizen scientists are helping them find those signs in the ocean’s coral reefs.


2009 Benjamin Franklin Medal Winner: Lotfi A. Zadeh
Wed, 07 Oct 2009 00:00:00 +0000 - The 2009 Benjamin Franklin Medal in Electrical Engineering is presented to Lotfi Zadeh for his invention and development of the field of fuzzy logic, a mathematical system that captures aspects of the ambiguity of human language and thought, which has solved problems in areas such as artificial intelligence and the automated control of machines.


Naps and Creativity
Wed, 30 Sep 2009 00:00:00 +0000 - Telling your boss you need a nap might not be the smartest thing to do at work, but scientific evidence is now on your side. As this ScienCentral News video explains, sleep researchers just released a new study that says naps over an hour long may boost creative problem solving.


Street Corner Science with Stephen Benkovic
Wed, 23 Sep 2009 00:00:00 +0000 - ScienCentral is taking science back to the people with our second installment of "Street Corner Science," the radical yet-simple concept in which a film crew and a renowned scientist are plunked down amidst a busy city center, and an impromptu Q&A session with the public ensues.


Girls Vs. Boys at Math
Fri, 11 Sep 2009 00:00:00 +0000 - Are men naturally better at math than women or is that just an out-dated stereotype? When former Harvard president Larry Summers said publicly in 2005 that men are innately better at math, many women were outraged. So a couple of women scientists decided to research it. This ScienCentral News video explains their report published this week.


Unfiltered: Girls Vs. Boys At Math
Thu, 10 Sep 2009 00:00:00 +0000 - "Unfiltered" is a recurring series where ScienCentral reporters give their personal thoughts on the stories they produce. This installment is based on the news story "Girls Vs. Boys At Math."


2009 Benjamin Franklin Medal Winner: Stephen Benkovic
Mon, 31 Aug 2009 00:00:00 +0000 - The 2009 Benjamin Franklin Medal in Life Science is presented to Stephen Benkovic for his groundbreaking contributions to our mechanistic understanding of enzymes, and for helping to unravel the complexities of the enzymes involved in DNA replication. This ScienCentral Video Profile explains.


As Goes GM
Mon, 01 Jun 2009 19:23:06 +0000 - I know a woman who is relentlessly, ridiculously optimistic. Everything is always for the best.


Reports From the River
Fri, 29 May 2009 17:55:34 +0000 - A new blog just debuted that we thought was worth sharing.


Thin Brains and Depression
Thu, 28 May 2009 17:26:15 +0000 - It's well known that depression in your family puts you at high risk of depression. Now researchers have found a structural difference in the brain that could explain why. Animation: 3-D brain scan, the cortex layer peels away, courtesy Bradley Peterson



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