CCQ Seminar: Yoshiteru Maeno

Title: SCES-NESS: Strongly-Correlated Electron Systems under Non-Equilibrium Steady States

Abstract: DC current can be a powerful tuning parameter of the electronic states of strongly correlated electron systems in the vicinity of Mott transitions. In this presentation, we give a short review on the research progress on the novel phenomena in the layered perovskite Ca2RuO4 and related materials.

Under DC current, Ca2RuO4 with a small Mott gap exhibits semimetallic transport behavior with giant diamagnetism at low temperatures [1]. We attribute this behavior to emergent “Mott semimetal” state, in which the upper and lower Hubbard bands become tiny electron and hole pockets with light quasiparticle masses responsible for the large diamagnetism.

The results imply that in a non-equilibrium steady state (NESS) introduced by DC current, a variety of Mott insulators with small gaps may be driven into novel electronic states.

This work was done mainly in collaboration with C. Sow, R. Numasaki, S. Yonezawa, F. Nakamura, T. Oka, S. Kitamura, K. Kuroki, J. Zhang, M. Liu, A. Millis, D. Shibata, T. Yoshida, and N. Kikugawa. This work was supported by JSPS KAKENHI Nos. JP26247060, JP15H05852, and JP15K21717.