Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Insight on Superconductors

01.08.2008
An important advance in understanding how the electrons in some materials become superconducting has been made by researchers from UC Davis, the Los Alamos National Laboratory and UC Irvine. The work, published July 31 in the journal Nature, could lead to a deeper understanding of superconductivity and to new materials that are superconducting at higher temperatures.

The team of researchers, led by Yi-feng Yang, a postdoctoral fellow at UC Davis, found a simple way to calculate the temperature at which a new state of matter, the Kondo liquid, emerges in the class of metal alloys called heavy-electron materials. At very low temperatures, these alloys can become superconductors that conduct electricity without resistance.

"We've found a framing concept for an important class of materials, which allows us to begin to understand how they relate to each other and perhaps to find new members of the group," said Yang's postdoctoral mentor and team member, David Pines, distinguished professor of physics at UC Davis and co-director of ICAM, the Institute for Complex Adaptive Matter.

Heavy electron materials are alloys of metals such as cerium, ytterbium and uranium. They contain both free-moving electrons that make them electrical conductors and a "Kondo" lattice of localized electrons. When the temperature of the material is lowered below a characteristic temperature, the localized electrons lose their magnetism as they become collectively "entangled" through quantum mechanical effects with the conduction electrons, which become heavy and form the Kondo liquid. At much lower temperatures these heavy electrons then become either magnetic or superconducting.

Yang received a fellowship from ICAM that enabled him to become "embedded" in an experimental group on heavy electron materials led by Joe D. Thompson at Los Alamos. With Thompson and Han-oh Lee at Los Alamos, and Zachary Fisk at UC Irvine, he reviewed 30 years of existing data on heavy-electron materials, plus new experimental data collected by Thompson and Lee, to establish a long-sought connection between single impurities and lattice behavior in these materials.

They found that the crucial temperature at which the Kondo liquid emerges depends in a remarkably simple way on the coupling of individual local spins to the conduction electrons, Pines said.

The discovery should help researchers find the organizing principles of heavy-electron superconductivity, because it clarifies the nature of the normal state out of which superconductivity emerges, Pines said.

The work was supported by the National Science Foundation and by the ICAM fellowship for Yang. ICAM is a multidisciplinary research program of the University of California that has 57 branches across the U.S. and globally, with its headquarters at UC Davis.

Andy Fell | EurekAlert!
Further information:
http://www.ucdavis.edu

More articles from Power and Electrical Engineering:

nachricht Improved stability of plastic light-emitting diodes
19.04.2018 | Max-Planck-Institut für Polymerforschung

nachricht Intelligent components for the power grid of the future
18.04.2018 | Christian-Albrechts-Universität zu Kiel

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Tiny microenvironments in the ocean hold clues to global nitrogen cycle

23.04.2018 | Earth Sciences

Joining metals without welding

23.04.2018 | Trade Fair News

Researchers illuminate the path to a new era of microelectronics

23.04.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>