Colo. scientists form new type of matter

Discovery could lead to faster computers, cheaper electricity

January 29, 2004|By Dennis O'Brien | Dennis O'Brien,SUN STAFF

Scientists announced yesterday that a chilly cloud of gas the width of a strand of hair created for a tenth of a second in a Colorado lab is a new type of matter - one that could lead to levitated trains, faster computers and cheaper electric bills.

The researchers say they produced the world's first fermionic condensate by chilling potassium atoms and applying a magnetic field, a process that forced the atoms to form pairs in the same way that electrons pair off when they produce superconductivity.

The work could help unlock the mystery of superconductivity, a phenomenon that physicists have studied for decades. Superconductors allow electricity to flow with no resistance.

"Ultimately, it could mean faster computers, smaller cell phones or the development of some technology we haven't even thought of," said James Gates, a physics professor at the University of Maryland, College Park.

The findings - the results of a race among six teams of physicists worldwide - were announced at a news conference yesterday by Deborah Jin, a researcher at the National Institute of Standards and Technology and a physics professor at the University of Colorado at Boulder.

The study was published yesterday in the online edition of Physical Review Letters.

Jin, who won a $500,000 MacArthur "genius" grant last year, said she chilled 500,000 potassium atoms to temperatures near absolute zero (minus 459 degrees Fahrenheit). That slowed the atoms down and prompted them to pair off and produce a gas cloud in ways that were never before observed.

She said the study yielded reliable results despite the gas cloud's small size and brief shelf life. The results were repeated in the lab hundreds of times, she said, and recorded on very precise lasers and other instruments.

Experts say the findings confirmed a decade-old theory that fermions - the basic building blocks of all matter - pair off before they form molecules.

"It's as if they get engaged before they get married," said Kurt Gibble, a physics professor at Penn State University who reviewed the paper. "It's goofy."

Another NIST researcher, Eric A. Cornell, shared the Nobel prize for physics in 2001 for discovering the Bose-Einstein condensate. That is a phenomenon where bosons - another type of particle - are chilled to a point at which they act as if they were a single element.

Cornell's work proved 80-year-old theories about how quantum particles would react when chilled to such low temperatures that atoms almost cease to move.

Cornell credited Jin yesterday with accomplishing a difficult task. "I doubt very much I could have made this experiment work," Cornell told reporters.

Researchers since the mid-1990s have created a number of Bose-Einstein condensates. But the Colorado team was the first to create and observe chilled fermions - which with bosons make up the particle family tree.

The findings are seen as a major breakthrough among physicists.

"It's a beautiful experiment," said John Thomas, a Duke University physicist who led one of the research groups vying with Jin in the race to observe the condensate.

Thomas said yesterday that he is not disappointed that Jin's team made the discovery first. There are a number of discoveries still out there, he said.

"The hope is by playing with the theories, you can apply the theories to what you learn about condensed matter systems and come up with practical applications," he said.

Thomas and Jin said there is no way of knowing what technologies might result from the work, or when they might be developed.

"We've opened the door. We don't know where it's going to lead or how long it's going to take to get there," Jin said. "If you had a superconductor you could transmit electricity with no losses. Right now something like 10 percent of all electricity we produce in the United States is lost. It heats up wires."

Ceramic superconductors, which conduct electricity with zero resistance, were discovered in 1987. But because of the costs and complicated technology, they are limited in use to magnetic resonance imaging technology, supercolliders built by scientific labs and a small number of other devices.

Superconductors in use require cooling the nitrogen or helium to temperatures of at least minus 100 degrees Fahrenheit as a part of the superconductivity process.

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