Anomalous Metallic Magnetic Domain Wall in Mott Transition System with Strong Spin-Orbit Coupling(Research)

Abstract

We report on the variation of bulk electronic state and charge transport property upon the metal-insulator transition in the pyrochlore-type iridate R_2Ir_2O_7, which is a correlated electron system with the strong spin-orbit coupling. We have identified a metallic bound state emerging at the magnetic domain wall in Mott insulating phase on the verge of Mott transition. Interestingly, the charge gap of bulk is nearly zero on the verge of Mott transition. The results can be interpreted in terms of the emergence of Weyl semimetallic state in-between the Mott insulating phase and metallic phase in this class of correlated electron system with strong spin-orbit coupling.