Giant orbital magnetoelectric effect and current-induced magnetization switching in twisted bilayer graphene.

ABSTRACT: Recently, quantum anomalous Hall effect with spontaneous ferromagnetism was observed in twisted bilayer graphenes (TBG) near 3/4 filling. Importantly, it was observed that an extremely small current can switch the direction of the magnetization. This offers the prospect of realizing low energy dissipation magnetic memories. However, the mechanism of the current-driven magnetization switching is poorly understood as the charge currents in graphenes are generally believed to be non-magnetic. In this work, we demonstrate that in TBG, the twisting and substrate induced symmetry breaking allow an out of plane orbital magnetization to be generated by a charge current. Moreover, the large Berry curvatures of the flat bands give the Bloch electrons large orbital magnetic moments so that a small cu

SUBMITTER: He WY 

PROVIDER: S-EPMC7125167 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature