Rice University physicists on the hunt for the origins of high-temperature superconductivity have published new findings this week about a material that becomes “schizophrenic”—simultaneously exhibiting the characteristics of both a metallic conductor and an insulator.
In a theoretical analysis in Physical Review Letters (PRL), Rice physicists Qimiao Si and Rong Yu offer an explanation for a strange series of observations described earlier this year by researchers at the Stanford Linear Accelerator Center in Menlo Park, Calif. In those experiments, physicists used X-rays to probe the behavior of electrons in superconducting materials made of potassium, iron, and selenium. The material becomes superconducting at extremely cold temperatures, and the experiments revealed that at a slightly higher temperature, the material exhibited a “schizophrenic” electronic state in which some electrons in the iron atoms became frozen in place while electrons in neighboring orbitals continued to move.
“We have proposed a unified phase diagram for the alkaline iron selenides in which this schizophrenic phase connects between the lower-temperature, superconducting phase at one extreme and a higher-temperature insulating phase at the other,” says Si, Rice’s Harry C. and Olga K. Wiess Professor of Physics and Astronomy.
To read more, click here.