Emergence of Chern metal in a moiré Kondo lattice

Abstract

A Chern metal is a two-dimensional metallic state of matter carrying chiral edge states. We report the observation of a Chern metal at the onset of the magnetic Kondo breakdown in a frustrated moiré Kondo lattice--angle-aligned MoTe 2 /WSe 2 bilayers. The state is compressible and is manifested by a nearly quantized Hall resistance and a finite longitudinal resistance arising from a bad metallic bulk. We demonstrate the presence of a chiral edge state by nonlocal transport measurements and current-induced quantum anomalous Hall breakdown. Magnetic circular dichroism measurements further reveal a magnetization plateau for the Chern metal before a metamagnetic transition at the Kondo breakdown. Our results open an opportunity for moiré engineering of exotic quantum phases through the interplay between band topology and Kondo interactions.