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!
Nano-scale process may speed arrival of cheaper hi-tech products
09.11.2018 | University of Edinburgh
Nuclear fusion: wrestling with burning questions on the control of 'burning plasmas'
25.10.2018 | Lehigh University
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly
The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...
Scientists developed specially coated nanometer-sized vehicles that can be actively moved through dense tissue like the vitreous of the eye. So far, the transport of nano-vehicles has only been demonstrated in model systems or biological fluids, but not in real tissue. The work was published in the journal Science Advances and constitutes one step further towards nanorobots becoming minimally-invasive tools for precisely delivering medicine to where it is needed.
Researchers of the “Micro, Nano and Molecular Systems” Lab at the Max Planck Institute for Intelligent Systems in Stuttgart, together with an international...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
12.11.2018 | Life Sciences
12.11.2018 | Materials Sciences
12.11.2018 | Physics and Astronomy