Quantum bar magnets in a transparent salt

Friday, June 15, 2012

Scientists have managed to switch on and off the magnetism of a new material using quantum mechanics, making the material a test bed for future quantum devices.

The international team of researchers led from the Laboratory for Quantum Magnetism (LQM) in Switzerland and the London Centre for Nanotechnology (LCN), found that the material, a transparent salt, did not suffer from the usual complications of other real magnets, and exploited the fact that its quantum spins ? which are like tiny atomic magnets - interact according to the rules of large bar magnets. The study is published in Science.

Anybody who has played with toy bar magnets at school will remember that opposite poles attract, lining up parallel to each other when they are placed end to end, and anti-parallel when placed adjacent to each other. As conventional bar magnets are simply too large to reveal any quantum mechanical nature, and most materials are too complex for the spins to interact like true bar magnets, the transparent salt is the perfect material to see what's going on at the quantum level for a dense collection of tiny bar magnets.

The team were able to image all the spins in the special salt, finding that the spins are parallel within pairs of layers, while for adjacent layer pairs, they are antiparallel, as large bar magnets placed adjacent to each other would be. The spin arrangement is called "antiferromagnetic". In contrast, for ferromagnets such as iron, all spins are parallel.

By warming the material to only 0.4 degrees Celsius above the absolute "zero" of temperature where all classical (non-quantum) motion ceases, the team found that the spins lose their order and point in random directions, as iron does when it loses its ferromagnetism when heated to 870 Celsius, much higher than room temperature because of the strong and complex interactions between electron spins in this very common solid.

The team also found that they could achieve the same loss of order by turning on quantum mechanics with an electromagnet containing the salt. Thus, physicists now have a new toy, a collection of tiny bar magnets, which naturally assume an antiferromagnetic configuration and for which they can dial in quantum mechanics at will.

"Understanding and manipulating magnetic properties of more traditional materials such as iron have of course long been key to many familiar technologies, from electric motors to hard drives in digital computers," said Professor Gabriel Aeppli, UCL Director of the LCN.

"While this may seem esoteric, there are deep connections between what has been achieved here and new types of computers, which also rely on the ability to tune quantum mechanics to solve hard problems, like pattern recognition in images."

###

University College London: http://www.ucl.ac.uk

Thanks to University College London for this article.

This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.

This press release has been viewed 54 time(s).

may day protests tony nominations 2012 facebook organ donor jessica simpson gives birth carrie underwood blown away chk capitals

Catholic hospitals reject birth control compromise

(AP) ? Sharpening an election-year confrontation over religious freedom and government health insurance rules, the nation's Catholic hospitals on Friday rejected President Barack Obama's compromise for providing birth control coverage to their women employees.

The Catholic Health Association was a key ally in Obama's health care overhaul, defying opposition from church bishops to help the president win approval in Congress. But the group said Friday it does not believe church-affiliated employers should have to provide birth control as a free preventive service, as the law now requires.

The hospital group's decision calls into question a compromise offered by the president himself only months ago, under which the cost of providing birth control would be covered by insurance companies and not religious employers. While churches and other places of worship are exempt from the birth control mandate, nonprofits affiliated with a religion, such as hospitals, are not.

In a letter to the federal Health and Human Services department, the hospital group said the compromise initially seemed to be "a good first step" but that examination of the details proved disappointing. The plan would be "unduly cumbersome" to carry out and "unlikely to adequately meet the religious liberty concerns" of all its members, the group said.

While some liberal-leaning religious groups see no problem with the birth control rule, Roman Catholic bishops and conservative-leaning groups are treating it as an affront and calling it an attack on religious freedom. Institutions ranging from the University of Notre Dame to Catholic Charities in several states to the Archdiocese of Washington have sued to block the rule.

With the Catholic Health Association now voicing concerns, opponents gained a powerful endorsement. There was no immediate reaction from the Obama administration.

The association represents about 600 hospitals and hundreds of nursing homes and other health-related organizations, totaling 2,000 members around the country. One of every six patients is cared for in a Catholic hospital.

In its letter, the group said the government should either broaden the exemption for religious employers, or pay directly for the birth control coverage.

Starting next Jan, 1, in most cases, women will have access to birth control at no additional charge through their job-based coverage, as part of a package of preventive services that also includes HIV screening and support for breast-feeding mothers. Some employers, considered to be "grandfathered" in under the health care law, will not have to provide the coverage.

The requirement applies to all birth control approved by the Food and Drug Administration. That includes the pill, intrauterine devices, the so-called morning-after pill, and newer forms of long-acting implantable hormonal contraceptives that are becoming widely used in the rest of the industrialized world.

The morning-after pill is particularly controversial. It has no effect if a woman is already pregnant, but many religious conservatives consider it tantamount to an abortion drug.

As recently as the 1990s, many health insurance plans didn't cover birth control. Protests, court cases, and new state laws led to dramatic changes. Today, almost all plans cover prescription contraceptives ? but usually impose copays.

The White House has struggled to find a solution that will satisfy women's rights advocates without offending people who object on grounds of religious freedom. While Catholic church teaching has long opposed artificial means of birth control, polls show the faithful use the pill nonetheless.

Obama in 2008 won the total Catholic vote, 54 percent to Sen. John McCain's 45 percent, but he lost the white Catholic vote, 52 percent to 47 percent, according to exit polls. Once reliably Democratic, Catholics are now swing voters, with white Catholics making up the majority of the group.

Associated Press

bcs rankings week 13 bcs rankings week 13 philadelphia marathon rhodes scholar cranberry sauce recipe mls cup amas 2011

Fresh Android Apps for June 15: Amazon Mobile update & Temple Run: Brave

The weekend is for shopping and fun, right? Now you can get your share of both with today?s week-ending Fresh Apps. Amazon Mobile saw a big update that makes the app both visually appealing and more functional. Meanwhile, a Disney-inspired version of Temple Run hit mobile devices, which should keep you busy all weekend long as you quest for the highest score.

An old stalwart on Android, it?s been a while since the official Amazon Mobile app received a significant update. Version 1.6 was pushed out to the Google Play store yesterday and it contains quite a few interesting enhancements, plus a design refresh that makes it look a little more crisp and clear.

There are new ways to sort and filter your search results, easier access to your cart, and smarter-looking drop-down menus for access to popular pages/sections. The app also lets you scan a barcode directly from the front page, wish lists are more accessible, there are a number of bug fixes, and internationalization was added for eight more countries.

It emerged a few hours later than its iOS counterpart admittedly, but it?s good to see Android users getting in on the action quickly nevertheless. This follow-up to the exceedingly popular Temple Run is a tie-in with the new Disney feature, Brave. It?s essentially a re-skin of the original but adds a few new features here and there plus a nice visual refresh.

Using familiar swipe-based controls, you?ll run, jump and slide your way through the wilds of Scotland, escaping from Mordu, the demon bear. Along the way, you?ll pick up coins which will let you purchase power-ups and enhancements. Temple Run: Brave introduces archery this time round ? shooting a target will earn extra coins.

Find more great Android games here

verizon galaxy nexus lawrence lessig lawrence lessig time magazine person of the year 2011 time magazine person of the year 2011 new orleans jazz fest new orleans jazz fest

Finally, A Texas-sized Solution on Immigration Policy by Alex Nowrasteh

by Alex Nowrasteh

Alex Nowrasteh is the immigration policy analyst at the Cato Institute's Center for Global Liberty and Prosperity.

Added to cato.org on June 13, 2012

This article appeared in Houston Chronicle on June 13, 2012.

The recent Texas state Republican Party convention in Fort Worth was boisterous, with attendees arguing about everything from party unity to foreign policy and what the GOP platform should read. The positive thing to emerge from the convention, however, is the evolving GOP stance on immigration.

A plank was inserted into the party platform to:

Create an Effective and Efficient Temporary Worker Program ? A national Temporary Worker Program should be implemented to bring skilled and unskilled workers into the United States for temporary periods of time when no U.S. workers are currently available.

That is a huge step in the right direction.

Our immigration system is a bureaucratic monstrosity in which officials frequently lose paperwork, fail to issue proper documentation, and delay cases for years. For most immigrants there is no visa category or way to enter the U.S. legally.

That's where Texas work visa provision comes in. The details are still vague but recreating something like the Bracero program, a temporary, unlimited, and lightly regulated work visa that was in place from 1942 to 1964, would be better than the present work visa system. The Bracero program pushed unauthorized workers into legal work visas, away from the informal economy, and provided a legal avenue for foreign workers and American employers to work together.

Nothing like it exists today. Current temporary visas like the H-2A for farm workers are so regulated, complicated, and expensive that unauthorized immigrants are often the cheaper option. According to a recent Georgia Department of Agriculture survey, farmers almost uniformly complained about the regulations and expense of the visa program. One frustrated farmer wrote, "I was 15-20 workers short this year. Due to laws that [a]ffected the migration of seasonal help." A plea for liberalization couldn't be clearer.

A 21st century Bracero that includes workers of all skills would dissolve much of the informal immigrant economy and allow employers to find the employees they need.

he Texas GOP has seen how restricting immigration has hurt other states. Arizona is the prime example. When its immigration laws forced roughly 200,000 unauthorized immigrants from the state they took their purchasing power, money, rents, and businesses with them. Arizona's economy declined more than its neighbors.

Arizona's immigration laws significantly expanded penalties for employers who knowingly hired unauthorized immigrants. For a second such offense, the business owner's licenses were permanently revoked. The mere threat of such an action has driven investments out of the state. Threatening to close businesses with immigration regulations is counterproductive to economic growth.

According to the Kauffman Foundation, 550 out of every 100,000 immigrants start a new business every month. For Hispanics, the largest immigrant group, the rate is 520. The native-born rate of business creation is 270. Overall in 2011, 28 percent of all new businesses started were started by immigrants despite them only representing about 13 percent of the American population.

The Texas GOP platform change also highlighted a major difference between itself and President Obama. When Obama was the junior senator from Illinois in 2007, he voted for a poison pill amendment introduced by then-Sen. Byron Dorgan, D-N.D., that gutted the essential guest worker reform provision in that year's immigration reform proposal. It passed 49 to 48 and Obama's vote for Dorgan's amendment was unexpected.

The Dorgan amendment was passed to appease labor unions who were worried about competition from guest workers. Ironically, the Bracero guest worker visa was also killed by union inspired opposition in the 1960s. Eliminating legal work channels in the 1960s led to the present mess with unauthorized immigration and it won't be solved without reopening them.

Adam Smith wrote in The Wealth of Nations that an open and prosperous economy requires the "free circulation of labour and stock, both from employment to employment and from place to place." Borders, wage controls, and regulations should not stand in the way of that profitable migration. The Texas GOP is beginning to hear that message.

The Texas GOP's position on immigration isn't perfect. The platform supports biometric identification and a limiting of birthright citizenship for the children of unauthorized immigrants, two terrible proposals. But those negative parts shouldn't overshadow the accomplishment of a major state GOP realizing that the only way forward on immigration is an increase in work permits and a liberalization of our immigration laws.

katharine mcphee cold mountain valentines day ideas the villages florida egoraptor gisele bundchen turbotax

Global Telecom Business Innovation Awards 2012 | Flickr - Photo ...

blade runner close encounters of the third kind norovirus beyonce and jay z baby droid 4 ann coulter tom brady sister

NASA chief to see history-making SpaceX capsule

(AP) ? NASA's administrator is to visit the history-making Dragon spacecraft at a Texas rocket factory.

Last month the world's first commercial supply ship delivered 1,400 pounds of old equipment to the International Space Station.

The California-based SpaceX is the first private business to send a cargo ship to the space station.

On Wednesday, NASA Administrator Charles Bolden and SpaceX Chief Executive Elon Musk will see the spacecraft at the company's rocket factory in McGregor, about 150 miles southwest of Dallas.

The unmanned cargo ship splashed down May 31 into the Pacific Ocean, capping off a nine-day test flight.

It was the first time since the space shuttles stopped flying last summer that NASA got back a big load from the space station. SpaceX hopes to launch another capsule in September.

Associated Press

jenny mccarthy houston weather dwyane wade magic mike trailer the night they drove old dixie down levon oklahoma city bombing

Rivals AMD and ARM unite, summon others to become 'heterogeneous'

Rivals AMD and ARM unite, summon others to become 'heterogeneous'Rumors of a hook-up between AMD and ARM have been circulating ever since someone coined the phrase "the enemy of Intel is my friend." As of today, however, that alliance is real and cemented in the form of the HSA Foundation -- a non-profit organization dedicated to promoting the dark arts of Heterogeneous System Architecture. It's a relatively old concept in computing, but the Foundation's founding partners (AMD, ARM, Imagination Technologies, MediaTek and Texas Instruments) all stand to gain from its wider adoption. How come? Because it involves boosting a chip's performance by making it use its various components as co-processors, rather than treating them as specialized units that can never help each other out.

In other words, while Intel pursues Moore's Law and packs ever-more sophisticated transistors into its CPUs, AMD, ARM and the other HSA pals want to achieve similar or better results through parallel computing. In most cases, that'll mean using the graphics processor on a chip not only for visuals and gaming, but also for general tasks and apps. This can already be achieved using a programming language called OpenCL, but AMD believes it's too tricky to code and is putting mainstream developers off. Equally, NVIDIA has long had its own language for the same purpose, called CUDA, but it's proprietary. Whatever niche is left in the middle, the HSA Foundation hopes to fill it with an easier and more open standard that is not only cross-OS but also transcends the PC / mobile divide. If it works, it'll give us a noticeable surge in computational power in everyday apps by 2014. If it fails, these new-found friends can go back to the less awkward custom of ignoring each other.

Continue reading Rivals AMD and ARM unite, summon others to become 'heterogeneous'

Rivals AMD and ARM unite, summon others to become 'heterogeneous' originally appeared on Engadget on Tue, 12 Jun 2012 13:30:00 EDT. Please see our terms for use of feeds.

Permalink   |   | Email this | Comments


chicago blackhawks dick clark elie wiesel giuliana rancic giuliana rancic temptations work hard play hard

Webcam System Models Your Movements And Emotions On A Lifelike Avatar

A new system created at Keio University will help add lifelike motion capture and emotion-sensing to apps, games, and design programs by scanning your face and body for cues. The system works on any PC and can recreate all of your facial expressions on a life-like human avatar. The test model lets the team turn a sullen grad student into a cute girl with long pigtails.

apple tv update new ipad release pregnant jessica simpson international womens day joe the plumber lra lra