Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > New Technique Reveals Hidden Properties of Ultracold Atomic Gases

A powerful new JILA technique reveals hidden properties of ultracold atoms in a superfluid, in which atoms form pairs like electrons in a superconductor. The JILA group focuses on the "crossover" stage (middle graphic) between the small pairs of a Bose-Einstein Condensate (left) and the extremely large pairs of a low-temperature superconductor (right).

Credit: C. Regal/JILA
A powerful new JILA technique reveals hidden properties of ultracold atoms in a superfluid, in which atoms form pairs like electrons in a superconductor. The JILA group focuses on the "crossover" stage (middle graphic) between the small pairs of a Bose-Einstein Condensate (left) and the extremely large pairs of a low-temperature superconductor (right).

Credit: C. Regal/JILA

Abstract:
Physicists at JILA, a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado at Boulder, have demonstrated a powerful new technique that reveals hidden properties of ultracold atomic gases.

New Technique Reveals Hidden Properties of Ultracold Atomic Gases

GAITHERSBURG, MD | Posted on August 6th, 2008

To develop the new technique, the scientists borrowed an idea used for nearly a century in the study of materials: photoemission spectroscopy. Traditional photoemission spectroscopy probes the energy of electrons in a material. The new photoemission spectroscopy technique, described in the Aug. 7 issue of Nature,* adapts this technique to study potassium atoms in an ultracold gas.

Photoemission spectroscopy is particularly powerful in revealing details of the pairing of electrons in high-temperature superconductors, which are solids that have zero resistance to electrical current at relatively high temperatures (but still below room temperature). The scientists at JILA study a very similar phenomenon: superfluidity (fluids that can flow with zero friction). Specifically, they study how atoms in a Fermi gas behave as they "cross over" from acting like a Bose Einstein Condensate (in which fermions pair up to form tightly bound molecules) to behaving like pairs of separated electrons in a superconductor.

In the crossover region, atoms in an ultracold gas exert very strong forces on each other, which masks their individual properties. To see the hidden behavior, JILA scientists apply a radio frequency field to a cloud of trapped, paired potassium atoms, ejecting a few atoms from the strongly interacting cloud. Then the laser trap is turned off so the gas can expand. Scientists make images and count the numbers of escaping atoms at different velocities. With this information, scientists can calculate the atoms' original energy states and momentum values back when they were inside the gas. Scientists then map the energy levels for all the original states of the atoms and can identify a particular pattern that shows the appearance of a large "energy gap," which represents the amount of energy needed to break apart a pair of atoms.

The new photoemission technique represents a huge jump in the information available to physicists who study ultracold gases. Traditionally, scientists could probe either the energy or momentum of these gases, not both. The new technique simultaneously probes the energy and momentum, allowing the scientists to study the microscopics involved in the pairing of two atoms.

"This technique is a clean probe of the microscopics in this system, and it allows us to see interesting things like a very large energy gap that seems to appear before the superfluid state," says group leader Deborah Jin, a JILA/NIST fellow. Another research group previously identified what seemed to be an energy gap; however, the results of the JILA technique are much clearer to interpret, Jin says.

Ultimately, the JILA work studying superfluidity in atomic gases may one day help in understanding the energy gap that appears in high-temperature superconductors, which may have applications such as more efficient transmission of electricity across power grids. In addition, the new technique can be extended beyond the study of pairing to include, for example, the study of atoms trapped in crisscrossed "lattices" of laser light, a building block for some atomic clock and quantum computer designs.

Funding for the research was provided by the National Science Foundation.

*J.T. Stewart, J.P. Gaebler and D.S. Jin. Using photoemission spectroscopy to probe a strongly interacting Fermi gas. Nature. Aug. 7, 2008.

####

About NIST
Founded in 1901, NIST is a non-regulatory federal agency within the U.S. Department of Commerce. NIST's mission is to promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life.

For more information, please click here

Contacts:
Laura Ost

(303) 497-4880

Copyright © NIST

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Stanford team achieves 'holy grail' of battery design: A stable lithium anode - Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode July 27th, 2014

Iranian Scientists Produce Reusable Nanoadsorbent to Detect Sulfamide in Chicken July 27th, 2014

Breakthrough laser experiment reveals liquid-like motion of atoms in an ultra-cold cluster: University of Leicester research team unlocks insights into creation of new nano-materials July 25th, 2014

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

Physics

Physicists Use Computer Models to Reveal Quantum Effects in Biological Oxygen Transport: The team solved a long-standing question by explaining why oxygen and not deadly carbon monoxide preferably binds to the proteins that transport it around the body. July 17th, 2014

Flashes of light on the superconductor: Using light to modulate the properties of a copper-based superconductor July 15th, 2014

Weizmann Institute scientists take another step down the long road toward quantum computers July 14th, 2014

University of Illinois study advances limits for ultrafast nano-devices July 10th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Stanford team achieves 'holy grail' of battery design: A stable lithium anode - Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode July 27th, 2014

New imaging agent provides better picture of the gut July 25th, 2014

A*STAR and industry form S$200M semiconductor R&D July 25th, 2014

NNCO Announces an Interactive Webinar: Progress Review on the Coordinated Implementation of the National Nanotechnology Initiative 2011 Environmental, Health, and Safety Research Strategy July 23rd, 2014

Discoveries

Stanford team achieves 'holy grail' of battery design: A stable lithium anode - Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode July 27th, 2014

Iranian Scientists Produce Reusable Nanoadsorbent to Detect Sulfamide in Chicken July 27th, 2014

New imaging agent provides better picture of the gut July 25th, 2014

Breakthrough laser experiment reveals liquid-like motion of atoms in an ultra-cold cluster: University of Leicester research team unlocks insights into creation of new nano-materials July 25th, 2014

Announcements

Stanford team achieves 'holy grail' of battery design: A stable lithium anode - Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode July 27th, 2014

Iranian Scientists Produce Reusable Nanoadsorbent to Detect Sulfamide in Chicken July 27th, 2014

Breakthrough laser experiment reveals liquid-like motion of atoms in an ultra-cold cluster: University of Leicester research team unlocks insights into creation of new nano-materials July 25th, 2014

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE