Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Black holes: a model for superconductors?

03.03.2011
Black holes are some of the heaviest objects in the universe. Electrons are some of the lightest. Now physicists at the University of Illinois at Urbana-Champaign have shown how charged black holes can be used to model the behavior of interacting electrons in unconventional superconductors.

"The context of this problem is high-temperature superconductivity," said Phillips. "One of the great unsolved problems in physics is the origin of superconductivity (a conducting state with zero resistance) in the copper oxide ceramics discovered in 1986." The results of research by Phillips and his colleagues Robert G. Leigh, Mohammad Edalati, and Ka Wai Lo were published online in Physical Review Letters on March 1 and in Physical Review D on February 25.

Unlike the old superconductors, which were all metals, the new superconductors start off their lives as insulators. In the insulating state of the copper-oxide materials, there are plenty of places for the electrons to hop but nonetheless—no current flows. Such a state of matter, known as a Mott insulator after the pioneering work of Sir Neville Mott, arises from the strong repulsions between the electrons. Although this much is agreed upon, much of the physics of Mott insulators remains unsolved, because there is no exact solution to the Mott problem that is directly applicable to the copper-oxide materials.

Enter string theory—an evolving theoretical effort that seeks to describe the known fundamental forces of nature, including gravity, and their interactions with matter in a single, mathematically complete system.

Fourteen years ago, a string theorist, Juan Maldacena, conjectured that some strongly interacting quantum mechanical systems could be modeled by classical gravity in a spacetime having constant negative curvature. The charges in the quantum system are replaced by a charged black hole in the curved spacetime, thereby wedding the geometry of spacetime with quantum mechanics.

Since the Mott problem is an example of strongly interacting particles, Phillips and colleagues asked the question: "Is it possible to devise a theory of gravity that mimics a Mott insulator?" Indeed it is, as they have shown.

The researchers built on Maldacena's mapping and devised a model for electrons moving in a curved spacetime in the presence of a charged black hole that captures two of the striking features of the normal state of high-temperature superconductors: 1) the presence of a barrier for electron motion in the Mott state, and 2) the strange metal regime in which the electrical resistivity scales as a linear function of temperature, as opposed to the quadratic dependence exhibited by standard metals.

The treatment advanced in the paper published in Physical Review Letters shows surprisingly that the boundary of the spacetime consisting of a charged black hole and weakly interacting electrons exhibits a barrier for electrons moving in that region, just as in the Mott state. This work represents the first time the Mott problem has been solved (essentially exactly) in a two-dimensional system, the relevant dimension for the high-temperature superconductors.

"The next big question that we must address," said Phillips, "is how does superconductivity emerge from the gravity theory of a Mott insulator?"

This research was supported by the NSF DMR-0940992 and the Center for Emergent Superconductivity, a DOE Energy Frontier Research Center, Award Number DE- AC0298CH1088, and by DOE grant FG02-91-ER40709. The conclusions presented are those of the authors and not necessarily those of the funding agencies.

Philip Phillips | EurekAlert!
Further information:
http://www.illinois.edu

More articles from Physics and Astronomy:

nachricht Nanomagnetism in X-ray Light
23.03.2017 | Max-Planck-Institut für Intelligente Systeme

nachricht When helium behaves like a black hole
22.03.2017 | University of Vermont

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

Vanishing capillaries

23.03.2017 | Health and Medicine

Nanomagnetism in X-ray Light

23.03.2017 | Physics and Astronomy

Pulverizing electronic waste is green, clean -- and cold

22.03.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>