Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

JILA Team Finds New Parallel Between Cold Gases and 'Hot' Superconductors

08.07.2010
Scientists at JILA, working with Italian theorists, have discovered another notable similarity between ultracold atomic gases and high-temperature superconductors, suggesting there may be a relatively simple shared explanation for equivalent behaviors of the two very different systems.

Described in Nature Physics,* the new research lends more support to the idea that JILA studies of superfluidity (flow with zero friction) in atomic gases may help scientists understand far more complicated high-temperature superconductors, solids with zero resistance to electrical current at relatively high temperatures. Known high-temperature superconductors only superconduct well below room temperature, but a detailed understanding of how the materials work may one day lead to practical applications such as more efficient transmission of electricity across power grids.

JILA is operated jointly by the National Institute of Standards and Technology (NIST) and the University of Colorado at Boulder.

The JILA group studies how atoms in a Fermi gas** behave as they "cross over" from acting like a Bose Einstein condensate, in which atom pairs form tightly bound molecules, to behaving like pairs of separated electrons in a superconductor. In the new study, JILA scientists applied a technique they developed in 2008 to explore subtle energy properties of ultracold atoms. The technique is an adaptation of photoemission spectroscopy, long used to probe the energy of electrons in materials. A superconductor research group recently used electron photoemission spectroscopy to find evidence of electron pairing above the critical temperature where the material switches from a superconductor to a regular conductor. Why this duality occurs is a subject of debate.

The JILA scientists performed comparable measurements for an ultracold gas of potassium atoms at and above temperatures where superfluidity disappears. Like the superconductor group, the JILA team found evidence of atom pairing above the critical temperature. This demonstrates the existence of a so-called "pseudo-gap region" where the system retains some pairs of correlated fermions but not all characteristics of superfluidity. The findings were made possible in part by significant improvements in the signal strength of the atom photoemission spectroscopy technique since 2008.

"What makes this really interesting is that the two systems are actually very different, with the high-temperature superconductor being much more complicated than atomic gases," says NIST/JILA Fellow Deborah Jin. "The observation of similar behavior with similar measurements suggests that having a pseudogap phase does not require complicated explanations, such as lattice effects, two-dimensionality, or exotic pairing mechanisms."

Co-authors of the new paper are theorists from the Universita di Camerino in Italy. The research was funded by the National Science Foundation.

* J.P. Gaebler, J.T. Stewart, T.E. Drake and D.S. Jin, A. Perali, P. Pieri and G.C. Strinati. 2010. Observation of pseudogap behavior in a strongly interacting Fermi gas. Nature Physics. Posted online July 4.

** A Fermi gas is a collection of noninteracting particles called fermions, one of two categories of fundamental particles found in nature (bosons are the other). Identical fermions cannot occupy the same place at the same time.

Laura Ost | Newswise Science News
Further information:
http://www.nist.gov

More articles from Physics and Astronomy:

nachricht Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst

nachricht Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>