Current Driven Magnetization Reversal in Orbital Chern Insulators

TL;DR

This paper proposes a novel current-driven mechanism for reversing magnetization in orbital Chern insulators, specifically in graphene multilayers with moiré minibands, involving a specific relation between current, magnetic field, and system parameters.

Contribution

It introduces a new theoretical mechanism for magnetization reversal driven by current in orbital Chern insulators, expanding understanding of control methods in topological materials.

Findings

Reversal lines in (I, B) space with specific slope formula.

Dependence of reversal on magnetization, moiré unit cell area, and chemical potential ratio.

Theoretical prediction of current-driven magnetization switching in graphene-based systems.

Abstract

Graphene multilayers with flat moir\'e minibands can exhibit the quantized anomalous Hall effect due to the combined influence of spontaneous valley polarization and topologically non-trival valley-projected bands. The sign of the Hall effect in these Chern insulators can be reversed either by applying an external magnetic field, or by driving a transport current through the system. We propose a current-driven mechanism whereby reversal occurs along lines in the (current $I$, magnetic-field $B$) control parameter space with slope $dI/dB = (e/h)\, M A_{M} \, (1-\gamma^2)/\gamma$, where $M$ is the magnetization, $A_M$ is the moir\'e unit cell area, and $\gamma <1$ is the ratio of the chemical potential difference between valleys along a domain wall to the electrical bias $eV$.