Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Emerging research suggests a new paradigm for "unconventional superconductors"

10.04.2014

An international team of scientists has reported the first experimental observation of the quantum critical point (QCP) in the extensively studied “unconventional superconductor” TiSe2, finding that it does not reside as predicted within the superconducting dome of the phase diagram, but rather at a full GPa higher in pressure.

The surprising result, reported in Nature Physics, suggests that the emergence of superconductivity in TiSe2 isn’t associated with the melting of a charge density wave (CDW), as prevailing theory holds; in fact the CDW’s amplitude decreases under increasing pressure, but does not disappear at zero resistance.


Artist's conception of charge density wave domain walls in TiSe2 and the emergence of superconductivity through their quantum fluctuations. Image by Young Il Joe

The researchers find that the emergence of superconductivity in this material is connected rather with the formation of domain walls between commensurate and incommensurate phase transitions. The discovery of this new phase boundary has implications for our understanding of superconducting behavior.

The experiments, conducted by Young Il Joe, a graduate student working with condensed matter physicist Peter Abbamonte, employed a novel X-ray scattering technique at the Cornell High Energy Synchrotron Source (CHESS) to obtain the first ever measurements of the degree of commensurability of the CDW order parameter.

In this, the researchers took advantage of the harmonics of the diffractive optics—usually filtered out in X-ray experiments—to take two readings simultaneously. The wavelengths of two simultaneous photon beams were carefully calibrated, one to measure the periodicity of the crystal lattice, the other to measure the periodicity of the electrons, and compare the two.

At low energies, the CDW was found to be commensurate, as expected, but above the superconducting dome, incommensurate behavior emerged as the temperature was increased. The superconducting characteristics of TiSe2 are typical of other unconventional superconducting materials that exhibit the universal phase diagram, suggesting a fundamental connection between unconventional superconductivity and the quantum dynamics of domain walls.

This work sheds new light on our understanding to the theorized connection between superconductivity and other ordered states, such as charge density wave (CDW), antiferromagnetism, or stripe order and could contribute to the eventual development of better superconducting materials, and ultimately to the possible invention of room-temperature superconductors.

The X-ray experiments were supported by the U.S. Department of Energy under Grant No. DE-FG02-06ER46285. Young Il Joe, Shi Yuan, and Lance Cooper grew the 1-TiSe2 crystals at the Frederick Seitz Materials Research Laboratory at the University of Illinois at Urbana-Champaign with support from DOE Grant No. DE-FG02-07ER46453. Use of the CHESS was supported by the National Science Foundation and the National Institutes of Health/National Institute of General Medical Sciences under NSF award DMR-0936384.

T.C. Chiang’s contributions were supported by DOE Grant No. DE-FG02-07ER46383. The conclusions presented are those of the scientists and not necessarily those of the funding agencies. Contact: Peter Abbamonte, Department of Physics, University of Illinois at Urbana-Champaign, 217/244-4861. Siv Schwink, communications coordinator, Department of Physics, University of Illinois at Urbana-Champaign, 217/300-2201.

Peter Abbamonte | EurekAlert!
Further information:
http://www.illinois.edu

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

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>