Research chip said to be 10x to 20x more powerful than chips in multicore Core family

By Sharon Gaudin

Intel Corp. is honing its sights on many-core chips that are far more powerful than today’s dual and quad-core processors.

As expected, Intel took a big step in that direction today by unveiling a 48-core research chip that it says is 10 to 20 times more powerful than the current top end offering in its multi-core Core line of processors. Intel also noted that the experimental chip uses the same amount of energy as two household light bulbs.

With its eye on the data center and the cloud, Intel built fully functional cores in the new chip as part of what it calls its “terascale” mission.

“With a chip like this, you could imagine a cloud data center of the future which will be an order of magnitude more energy efficient than what exists today, saving significant resources on space and power costs,” said Justin Rattner, Intel CTO and head of Intel Labs. “Over time, I expect these advanced concepts to find their way into mainstream devices, just as advanced automotive technology such as electronic engine control, air bags and anti-lock braking eventually found their way into all cars.”

Today’s unveiling of the 48-core research chip comes about two years after Intel showed off an experimental 80-core chip. That research chip had teraflop performance capabilities but used less energy than a quad-core processor.

The 80-cores were not fully functional, however, and the chip was used mainly to study ways to make a large number of cores communicate efficiently with each other, as well as help Intel engineers find new architectural and core designs.

At the time, Intel officials said that the company was five to eight years away from building a fully functional, commercial-ready 80-core chip.

In an interview with Computerworld last month, Rattner said that schedule has changed and that engineers are even closer to developing such a chip.

Intel reported today that it is bringing academics and experts from other high tech firms into the loop by distributing 100 of the experimental 48-core chips so researchers can work on programming models and on developing software that can run on such a high number of cores.

The chip maker, which is slated to unveil six- and eight-core Nehalem chips next year, also noted that it expects to integrate key features of the research chip into a new Core line of commercially available processors by early 2010.

“This is an indication that Intel can deliver on its multi-core strategy,” said Rob Enderle, an analyst with the Enderle Group. “It’s very important in that it helps validate what Intel contends can be done and it adds credibility to their roadmap. The 80-core chip was more for bragging rights and was more of a science experiment. This one is more of a prototype — less flashy but more functional. It is all part of the process of bringing something new to market.”

Article Continues – http://www.computerworld.com/s/article/9141688/Intel_unveils_energy_efficient_48_core_chip

Sub-surface scope: A new endoscope prototype takes images below the surface of organs and tissues. The scope works through a tiny one-by-one-millimeter mirror (above) that pivots, reflecting a laser beam to produce microscopic, three-dimensional images. The current prototype is narrower than the width of a dime (below).   Credit: Huikai Xei

An infrared-based endoscope scans tissue below the surface.

By Jennifer Chu

An endoscope equipped with an infrared laser and a tiny mirror might one day help physicians diagnose early signs of cancer and other diseases and aid in surgery. A researcher at the University of Florida has designed a prototype device that captures images up to two millimeters beneath the surface of tissues, providing high-resolution, three-dimensional images at video-rate speeds.

In typical endoscopy, doctors thread a long, thin, camera-equipped fiber through a patient’s airway or gastrointestinal tract to search out abnormalities. The images, displayed on a monitor in real time, can reveal signs of infection, internal bleeding, ulcers, and tumors on tissue surfaces. But today’s endoscopes only show a superficial picture–they don’t reveal what’s going on under the surface, such as early tumor development.

“Eighty-five percent of cancers originate from the epithelium, which is about two millimeters deep,” says Huikai Xie, associate professor of electrical and computer engineering and director of the Biophotonics and Microsystems Laboratory. In addition to its potential for detecting early signs of cancer, he says, the scope might prove useful as a surgical tool, helping surgeons determine how deep a tumor is embedded in tissue. “If you need to remove the tumor, the surgeons have a hard time determining when to stop. With a real-time, high-resolution tool, they will be sure.”

John Saltzman, a gastroenterologist and director of endoscopy at Brigham and Women’s Hospital, says such a technique would help identify early signs of cancer, particularly in the esophagus. In a condition called Barett’s esophagus, for example, cells lining the esophagus undergo a change that increases the risk of cancer, says Saltzman, who is not involved in the research. “This technology would be an advantage for us to detect such abnormalities.”

Instead of a tiny camera at the tip, Xie’s endoscope is equipped with an infrared scanner and a tiny mirror, which scans tissue layer by layer to provide a three-dimensional image with microscopic resolution. The technique is based on a method called optical coherence tomography (OCT)–as a laser beams through the arm of an OCT scope, it hits tissue, and reflects some light back, while the rest scatters. Different tissues, such as cancer versus normal tissue, reflect light differently. An interferometer measures the reflected light and subtracts the scattered light. Altering the length of the arm alters the depth at which light is directly reflected back, producing images of different layers, which together form a three-dimensional image. The method is similar to ultrasound technology, and is often called “optical ultrasound.”

Article Continues - http://www.technologyreview.com/biomedicine/24052/

Stained glass: These photos show the two electrodes that make up the color-changing part of an electrochromic window. The clear electrode on the left has has been impregnated with lithium. The dark electrode on the right been drained of ions.   Credit: NREL

Thin, battery-like films change color when the weather changes.

By Katherine Bourzac

Thirty percent of the energy used by buildings in the United States is spent making up for heat loss or gain through windows. That adds up to about $40 billion in electricity costs each year. Windows that change color in response to changes in the weather can help save on electricity costs by absorbing sunlight in the winter and reflecting it in the summer. Such windows have existed for awhile, but they are expensive and not widely used. Now researchers are developing cheap printing methods for making these electrochromic systems, and hope to make electrochromic films that can be cut to fit existing windows.

Electrochromic windows sandwich materials that change color when a small electrical field is applied across them. This change is triggered by changes in light or temperature measured by sensors. “With electrochromic windows, everything happens dynamically–you don’t have to think about it,” says Anne Dillon, senior scientist at the National Renewable Energy Laboratory (NREL). “The problem is, they’re too expensive.”

This week at the Materials Research Society meeting in Boston, Dillon and research scientist Robert Tenent at NREL presented their new and potentially cheaper method for making electrochromic windows.

Typical electrochromic systems are made up of two electrodes separated by an electrolyte that shuttles ions between them. The electrode materials, usually oxidized metals, change color when an ion such as lithium moves into and out of them.

The NREL systems are based on electrodes made of nickel oxide and tungsten oxide and are the first electrochromic systems to be made by spraying down cheap precursors and then heating them. NREL has tested the systems using a liquid electrolyte, and is currently developing systems that rely on solid ion conductors. When a voltage is applied across the NREL system, lithium ions move out of the nickel oxide and into the electrolyte; on the other side, lithium ions move into the tungsten oxide. The movement of the ions causes the two electrodes to color.

Spraying the films is not only a cheaper alternative, says Tenent, it also provides some advantages in performance. The NREL team found that adding a small amount of lithium to the nickel-oxide ink solution before it’s printed made for a film that changes color much faster and within a wider range. In 29 seconds, as lithium leaves the nickel electrode and it darkens in color, the electrode goes from transmitting 80 percent of incident light to transmitting just 30 percent. Adding a small amount of lithium using conventional manufacturing techniques would be much more difficult, Tenent says.

There are other ways to make color-changing windows–by using materials that undergo a chemical change in response to light, for example. But these materials are prone to degradation. The NREL group is developing the metal-oxide electrodes in the hopes that these materials, which are robust and don’t degrade in response to light, will have long lifetimes.

So far, the NREL system has been tested on glass substrates. To make a truly affordable window coating, the group is working to make electrochromic films based on flexible, transparent plastics. The group is talking to DuPont, which makes plastics, about collaborating to fabricate electrochromic films sandwiched between one of the company’s heat-tolerant polymers. The nickel-oxide precursor must be heated to about 300 ºC in order to form the electrode material, a temperature many plastics can’t tolerate.

http://www.technologyreview.com/energy/24049/

As part of a new privacy campaign from the Center for Democracy and Technology, a new browser bookmarklet will let you flag privacy problems with a click, then have the reports forwarded to the Federal Trade Commission.

By Nate Anderson

See a website that appears to be misusing your personal information it? Bookmark it—and have the site information fed directly to the Federal Trade Commission.

The bookmarklet privacy tool is one part of a new campaign from the Center for Democracy and Technology, called “Take Back Your Privacy,” which launched today. The campaign comes only days before the FTC launches a new set of discussions on data privacy, and CDT wants to see some rules with real teeth to them.

What are the problems that need solving? According to the CDT, they are legion:

• The United States lacks a comprehensive federal law protecting consumer privacy.
• The most infamous privacy breaches of the past decade may never have come to light, were it not for a seminal California law. In 2002, the State of California passed a law that requires companies to notify consumers in the event that their personal information is compromised by a data breach.
• Even if you delete cookies, your browsing history, and your browser cache from your Web browser, many Web sites can still track you through “flash cookies” they have placed elsewhere on your computer.
• You are almost always carrying a tracking device by your side: your cell phone. Every few seconds, whenever it is turned on, your cell phone sends out a signal registering its location—and your location—with the nearest towers.
• You can still be identified in an “anonymized” data set. In August 2006, AOL publicly released “anonymized” log files containing twenty million search queries for over 650,000 users over a 3-month period; the data included a unique identifier for each user but did not include anything that would traditionally have been considered “Personally Identifiable Information” Nevertheless, several researchers were easily able to identify individuals based on these “anonymous” records. The New York Times even interviewed one of them.
• A 2009 study on behavioral advertising found that 86 percent of young adults reject advertisements that are tailored based on their activities across multiple Web sites. If the advertisements are tailored based on information gathered about their offline behavior, then 90 percent of young adults want nothing to do with these ads.

News this week that law enforcement had asked just one mobile provider, Sprint, for a staggering 8 million bits of cell phone tracking data would seem to have been a fortuitous revelation for CDT, as it makes the privacy issue concrete and immediate. Vague concern about the information that some retailer or website might be collecting about your buying habits doesn’t generate the same level of outrage as do revelations that your phone has actually become a homing beacon.

To collect data on one sort of privacy problem, CDT has also launched a downloadable bookmarklet. Slap it in your browser’s bookmark bar and then hit the bookmark whenever you navigate to a page that seems to be abusing your privacy.

Information will be collected by CDT and forwarded to the FTC in bulk once a month, though of course there’s no guarantee that the feds will act on any of it. If it garners significant usage, the tool could be a nice way to “red flag” the most egregious online privacy abuses, giving the FTC some idea of where to apply its limited investigative resources.

http://arstechnica.com/tech-policy/news/2009/12/website-invading-your-privacy-bookmark-it-and-alert-the-ftc.ars

In the US, Ford is still behind the 5 major foreign auto makers in fuel efficiency, surpassing only GM and Chrysler. Yet Ford of Europe already achieves dazzling mileage that we Americans can only dream of.

Imagine a gas-fueled car that gets 62 miles to the gallon: “With start-stop, regenerative brakes and an Eco Mode system, the new Focus gets 62 MPG (U.S.) on the European scale and emits just 99 grams of CO2 per kilometer” Available in Europe next Spring.

What is even more startling about this achievement by European Ford is that this mileage is achieved with just good old-fashioned tweaks on the traditional ICE gas car. There is no major technological breakthrough.

Why doesn’t Ford make cars like that here?

Article continues: http://www.matternetwork.com/2009/12/european-legislation-creates-62-mpg.cfm

http://www.enn.com/business/article/40782

Volkswagen’s Up! Lite concept.

Volkswagen staged the world premiere of the Up! Lite concept at the LA Auto Show. The new concept, based on Volkswagen’s New Small Family (the Up! models), incorporates a variation on the two-cylinder TDI hybrid powertrain from the L1 concept unveiled earlier this year at the Frankfurt Motor Show. (Earlier post.)

The door, five-seat concept offers combined EPA cycle fuel consumption of 2.44 L/100km (96 mpg US), with 70 mpg highway. The poewrtrain comprises an 800cc, 2-cylinder TDI (turbo-diesel), electric motor and 7-speed Direct Shift Gearbox (DSG). Combined with aerodynamics of Cd 0.237, the concept has reduced CO₂ emissions to 65 g/km.

<!––>Many of the components of the 695 kg (1,500 lbs) Volkswagen are based on those of the future New Small Family, an entirely new model series that is already scheduled for market launch in initial countries at the end of 2011; Volkswagen executives at the show said the Up Lite! might be commercialized.

The newly designed 0.8 TDI two-cylinder turbo-diesel engine delivers power of 38 kW / 51 hp. Furthermore, the electric motor (10 kW)—designed as a pulse start module (starter, alternator and E-drive)—also reduces the load of the TDI, provides added propulsion (boosting) and works to recover kinetic energy (regenerative braking). During boost phases, the TDI and E-motor combine for a total power of 48 kW / 64 hp.

Between 1,800 and 2,250 rpm the 55 kilogram light turbo-diesel direct injection engine delivers 120 N·m (89 l b-ft) maximum torque. Anyone wishing to benefit from the car’s full savings potential and attain a combined fuel consumption value of 2.44 liters will need to press the “Eco” button, activating an operating mode that reduces the engine’s power output to 26 kW / 36 PS.

Since they share a common construction as an engine family, the 0.8 TDI and the 1.6 TDI have an identical cylinder spacing (88 millimeters), identical bore (79.5 millimeters) and stroke (80.5 millimeters). In addition, these TDI engines share important internal engine details for reducing emissions. They include special piston recesses, multiple injection and special tuning of the individual injection jets.

In both cases, the technical package includes exhaust gas recirculation, oxidation catalytic converter and diesel particulate filter. Both TDIs exhibit especially quiet and low-vibration operation thanks to common rail injection. The aluminium crankcase was also built with a high degree of form precision, resulting in very low friction losses.

In two of its operating phases, the hybrid drive of the Up! Lite was designed to operate without any TDI propulsion at all.

• In coast-down, activated by the driver taking his or her foot off the gas pedal (car coasts, TDI engine is shut off).
• For shorter distances of up to 2 km (1.2 miles), e.g. in residential areas, the E-motor can power the Up! Lite all by itself. In this case, a lithium-ion battery supplies the energy.

Since it is capable of pure electric driving, the configuration is classified as a full hybrid. Shifting work is handled by a 7-speed Direct Shift Gearbox (DSG) like the one used in the new Polo. Moreover, the Volkswagen is equipped with a Stop-Start system.

The Up! Lite concept features a weight-optimized mix of metals.

The car features a safety frame of aluminium, steel and carbon fiber. The Volkswagen concept has a top speed of 160 km/h (100 mph) and accelerates to 100 km/h in 12.5 seconds.

The vehicle uses active thermal management with the radiator grille closing and opening automatically depending on the cooling needs of the engine (although te grille failed to open during the demonstration at the unveil). When the car is parked in the summer, hot air is vented to outside the vehicle (passive park ventilation). Instead of a classic rearview mirror, the Up! Lite uses three cameras to perform this function.

http://www.greencarcongress.com/2009/12/uplite-20091202.html

By David Hambling

Yves Rossy, aka “Jet man” and “Fusion Man,” has grabbed headlines with his jet-powered flights with an 8-foot wing strapped to his back. But he could be joined sometime soon by commandos on an airborne assault.

Last year, Rossy successfully flew 22 miles across the English Channel. Last week’s attempt to cross from Africa to Europe by flying from Morocco to Spain was less successful. Strong winds were against him, and Rossy ended up in the sea three miles short of the coast. Undaunted, the Swiss former military pilot now plans to fly across the Grand Canyon.

Rossy has reportedly refused requests from the military and stated that his powered wing, which cost more than $190,000 to develop, is only for aviation enthusiasts. However, he’s not the only one in the wingsuit business.

The Special Parachute and Logistics Consortium, is a German venture between two companies with expertise in this area. SPELCO produces a variety of parachute systems, helmets, oxygen supplies and other gear and services. But their most eye-catching project is the Gryphon Next Generation Parachute System (PDF, pictured).

This is described as a modular upgrade for parachute systems for use in “high-altitude, high-opening” jump missions, typically carried out by Special Forces. This 6-foot wing gives a glide ratio of 5:1, which means that a drop from 30,000 feet will allow you to glide about 30 miles. The makers estimate that this would take around 15 minutes, giving an average speed of about 60 miles an hour.

“All equipment is hidden in a lifting body optimized for stealth, the radar-signature is extremely low,” says the Gryphon data sheet (PDF). “Detection of incoming Gryphon soldiers by airborne or ground radar will be extremely difficult.”

Gryphon has a guidance system and heads-up display navigation. Best of all, the company are looking at an option for bolting on small engines similar to those used in Yves Rossy’s setup. These will increase the range to more than 60 miles, but will also make it possible to cover long distances from low altitude so that the entire mission can be more stealthy.

The company does not seem to have had any public offers for Gryphon yet — although, given the nature of likely customers, those offers might be kept relatively quiet.

Wingsuits are an addition to normal parachutes that allow better gliding. A parachute has to be deployed in order to land. However, wingsuit skydivers want to overcome this and are developing techniques to land safely without a parachute. This sounds like a practically suicidal manuever, but it seems likely that in the next few years technology and the careful application of technique will make it possible to land with a wingsuit alone. It’s certainly possible from a theoretical aerodynamic point of view, but whether it’s practical may be another matter.

This might just be the future for ultrastealthy airborne assault. Aided by extremely precise instruments and a flight computer, the wingman comes in at low level and high speed, before pulling up and dropping gently to the ground at exactly the right spot. It might sound wild, but it would certainly surprise the bad guys.

Illo:  SPELCO

http://www.wired.com/dangerroom/2009/12/look-out-below-wingsuits-pushed-for-airbone-assaults/

By Eliot Van Buskirk

Tim Quirk, a senior vice president at the digital music service Rhapsody, used to front a band that was signed to one of the major labels, Warner Bros.

His experiences at Rhapsody taught him firsthand that it’s possible to build a big database that accounts for what each copyright holder is owed. However, he and others contend, major labels have no incentive to put such a transparent database in place — quite the opposite: They only stand to benefit by obfuscating the accounting process for middle- and long-tail bands and tracking their digital streams and downloads casually.

Quirk estimated that his band’s three out-of-print major-label releases should have earned between two and five times as much digital revenue as its four independently-released albums earned, given that they are “far more popular.”

But when he compared IODA’s payouts to Warner Bros.’ payouts over the same five-year period, he was shocked to discover the reverse to be true.

His band earned about $12,000 from the independent albums distributed digitally through IODA, but only $62.47 from Warner Bros., so $395,214.71 of the band’s advance remains unrecouped (meaning that it owes that amount against future royalties earned).

Quirk (right) doesn’t think his band will ever recoup that sizable advance, but it’s the principle of the thing. By refusing to update their accounting technology for dealing with revenue from digital streams and downloads — data that digital music services such as Rhapsody and iTunes already deliver to the label anyway — he claims major labels are letting all sorts of digital revenue slip through the cracks and into their coffers, not to mention absorbing large upfront royalty advances from music start-ups.

“We all know that major labels are supposed to be venal masters of hiding money from artists, but they’re also supposed to be good at it, right?” asks Quirk in his post.

The whole saga makes for a fascinating (if somewhat lengthy) read.

Clarification: Although Quirk’s post says he “doesn’t necessarily subscribe to [the theory] that labels and publishers deliberately avoid creating the transparent accounting systems today’s technology enables,” it also says, “what’s so weird about this, to me: they have the ability to tell the truth, and doing so won’t cost them anything.”

Update: Warner Music Group issued a statement: “As a matter of policy, we don’t comment on specific terms of artists’ agreements. Accurate accounting to our artists is a high priority for WMG. We take these issues seriously and Mr. Quirk’s implications to the contrary are flat-out wrong.”

Update: Rhapsody issued a statement: “Tim Quirk’s views are his own and do not reflect those of Rhapsody management. Rhapsody and our label partners are focused on ensuring that artists and copyright holders are compensated appropriately. After years of working together with Warner Music, we believe the company has made every effort to provide accurate accounting to its artists and copyright holders. The number of parties involved makes this a very complex problem to solve, but one that we, as an industry, are committed to solving.”

See Also:

• Streamlining the Search for Music
• Free Music Equals Net Profits
• Independence Day for Indie Bands
• Report: Beatles’ Rock Band Royalties Could Reach $40 Million
  
• Sony Buys Part of the Long Tail

(Image courtesy of Too Much Joy) Photo of Tim Quirk: Flickr/penmachine

http://www.wired.com/epicenter/2009/12/major-label-messes-with-wrong-guy/

This image from the Japanese Advanced Satellite for Cosmology and Astrophysics shows the X-ray glow of the 100-million-degree Fahrenheit gas that fills the Perseus cluster. The white box indicates the area explored by the Suzaku X-ray telescope to detect chromium and manganese. The image is about two degrees wide, or four times the apparent width of a full moon. (Credit: JAXA)

Every cook knows the ingredients for making bread: flour, water, yeast, and time. But what chemical elements are in the recipe of our universe?

Most of the ingredients are hydrogen and helium. These cosmic lightweights fill the first two spots on the famous periodic table of the elements.

Less abundant but more familiar to us are the heavier elements, meaning everything listed on the periodic table after hydrogen and helium. These building blocks, such as iron and other metals, can be found in many of the objects in our daily lives, from teddy bears to teapots.

Recently astronomers used the Suzaku orbiting X-ray observatory, operated jointly by NASA and the Japanese space agency, to discover the largest known reservoir of rare metals in the universe.

Suzaku detected the elements chromium and manganese while observing the central region of the Perseus galaxy cluster. The metallic atoms are part of the hot gas, or “intergalactic medium,” that lies between galaxies.

“This is the first detection of chromium and manganese from a cluster,” says Takayuki Tamura, an astrophysicist at the Japan Aerospace Exploration Agency who led the Perseus study. “Previously, these metals were detected only from stars in the Milky Way or from other galaxies. This is the first detection in intergalactic space.”

The cluster gas is extremely hot, so it emits X-ray energy. Suzaku’s instruments split the X-ray energy into its component wavelengths, or spectrum. The spectrum is a chemical fingerprint of the types and amounts of different elements in the gas.

The portion of the cluster within Suzaku’s field of view is some 1.4 million light-years across, or roughly one-fifth of the cluster’s total width. It contains a staggering amount of metal atoms. The chromium is 30 million times the sun’s mass, or 10 trillion times Earth’s mass. The manganese reservoir weighs in at about 8 million solar masses.

Exploding stars, or supernovas, forge the heavy elements. The supernovas also create vast outflows, called superwinds. These galactic gusts transport heavy elements into the intergalactic void.

Harvesting the riches of the Perseus Cluster is not possible. But researchers will mine the Suzaku X-ray data for scientific insights.

“By measuring metal abundances, we can understand the chemical history of stars in galaxies, such as the numbers and types of stars that formed and exploded in the past,” Tamura says.

The Suzaku study data show it took some 3 billion supernovas to produce the measured amounts of chromium and manganese. And over periods up to billions of years, superwinds carried the metals out of the cluster galaxies and deposited them in intergalactic space.

A complete history of the universe should include an understanding of how, when, and where the heavy elements formed — the chemical elements essential to life itself. The Suzaku study contributes to a larger ongoing effort to take a chemical census of the cosmos. “It’s a part of learning the entire history of chemical element formation in the universe,” notes Koji Mukai, who heads the Suzaku Guest Observer program at NASA’s Goddard Space Flight Center in Greenbelt, Md.

With more than 10,000 galaxy clusters known, astronomers have just barely begun their work. “The current Suzaku result cannot answer these big questions immediately,” Tamura says, “but it is one of the first steps to understand the chemical history of the universe.”

The study appeared in the November 1 issue of The Astrophysical Journal Letters.

Story Source:

Adapted from materials provided by NASA/Goddard Space Flight Center, via EurekAlert!, a service of AAAS.

1. T. Tamura, Y. Maeda, K. Mitsuda, A. C. Fabian, J. S. Sanders, A. Furuzawa, J. P. Hughes, R. Iizuka, K. Matsushita, and T. Tamagawa. X-ray Spectroscopy of the Core of the Perseus Cluster with Suzaku: Elemental Abundances in the Intracluster Medium. The Astrophysical Journal, 2009; 705 (1): L62 DOI: 10.1088/0004-637X/705/1/L62

http://www.sciencedaily.com/releases/2009/12/091202172211.htm

A pair of laser beams (red arrows) impinges upon an ultracold gas cloud of rubidum atoms (green oval) to create synthetic magnetic fields (labeled Beff). (Inset) The beams, combined with an external magnetic field (not shown) cause the atoms to “feel” a rotational force; the swirling atoms create vortices in the gas. (Credit: JQI)

Achieving an important new capability in ultracold atomic gases, researchers at the Joint Quantum Institute, a collaboration of the National Institute of Standards and Technology (NIST) and the University of Maryland, have created “synthetic” magnetic fields for ultracold gas atoms, in effect “tricking” neutral atoms into acting as if they are electrically charged particles subjected to a real magnetic field.

The demonstration, described in the latest issue of the journal Nature, not only paves the way for exploring the complex natural phenomena involving charged particles in magnetic fields, but may also contribute to an exotic new form of quantum computing.

As researchers have become increasingly proficient at creating and manipulating gaseous collections of atoms near absolute zero, these ultracold gases have become ideal laboratories for studying the complex behavior of material systems. Unlike usual crystalline materials, they are free of obfuscating properties, such as impurity atoms, that exist in normal solids and liquids. However, studying the effects of magnetic fields is problematic because the gases are made of neutral atoms and so do not respond to magnetic fields in the same way as charged particles do. So how would you simulate, for example, such important exotic phenomena as the quantum Hall effect, in which electrons can “divide” into quasiparticles carrying only a fraction of the electron’s electric charge?

The answer Ian Spielman and his colleagues came up with is a clever physical trick to make the neutral atoms behave in a way that is mathematically identical to how charged particles move in a magnetic field. A pair of laser beams illuminates an ultracold gas of rubidium atoms already in a collective state known as a Bose-Einstein condensate. The laser light ties the atoms’ internal energy to their external (kinetic) energy, modifying the relationship between their energy and momentum. Simultaneously, the researchers expose the atoms to a real magnetic field that varies along a single direction, so that the alteration also varies along that direction. In a strange inversion, the laser-illuminated neutral atoms react to the varying magnetic field in a way that is mathematically equivalent to the way a charged particle responds to a uniform magnetic field. The neutral atoms experience a force in a direction perpendicular to both their direction of motion and the direction of the magnetic field gradient in the trap. By fooling the atoms in this fashion, the researchers created vortices in which the atoms swirl in whirlpool-like motions in the gas clouds. The vortices are the “smoking gun,” Spielman says, for the presence of synthetic magnetic fields.

Previously, other researchers had physically spun gases of ultracold atoms to simulate the effects of magnetic fields, but rotating gases are unstable and tend to lose atoms at the highest rotation rates. In their next step, the JQI researchers plan to partition a nearly spherical system of 20,000 rubidium atoms into a stack of about 100 two-dimensional “pancakes” and increase their currently observed 12 vortices to about 200 per-pancake. At a one-vortex-per-atom ratio, they could observe the quantum Hall effect and control it in unprecedented ways. In turn, they hope to coax atoms to behave like a class of quasiparticles known as “non-abelian anyons,” a required component of “topological quantum computing,” in which anyons dancing in the gas would perform logical operations based on the laws of quantum mechanics.

Story Source:

Adapted from materials provided by National Institute of Standards and Technology.

1. Lin et al. Synthetic magnetic fields for ultracold neutral atoms. Nature, 2009; 462 (7273): 628 DOI: 10.1038/nature08609

http://www.sciencedaily.com/releases/2009/12/091202131629.htm