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!
Did you know that the wrapping of Easter eggs benefits from specialty light sources?
13.04.2017 | Heraeus Noblelight GmbH
To e-, or not to e-, the question for the exotic 'Si-III' phase of silicon
05.04.2017 | Carnegie Institution for Science
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences