Current-Driven Magnetization Reversal in Orbital Chern Insulators

Graphene multilayers with flat moire minibands can exhibit the quantized anomalous Hall effect due to the combined influence of spontaneous valley polarization and topologically nontrivial 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 1, magnetic-field B) control parameter space with slope dI/dB = (e/h)MA(M) (1-gamma(2))/gamma, where M is the magnetization, A(M) is the moire 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.

Automated summary

This study explores the quantized anomalous Hall effect in graphene multilayers with flat moire minibands, and suggests a current-driven mechanism for reversing the sign of the Hall effect in these Chern insulators.