Prediction of quantum anomalous Hall effect on graphene nanomesh

Abstract

A quantum anomalous Hall effect (QAHE) has been realized in the Cr-doped magnetic topological insulator at an extremely low temperature (∼30 mK). From first-principles, we predict that QAHE can also be achieved in a well-designed graphene nanomesh without the requirement of transition metal doping. The ferromagnetic ordering arises mainly from the in-plane p_xy orbitals, leading to a Curie temperature of 830 K. The bulk band gap due to the intrinsic spin–orbital coupling (SOC) of the p_xy orbitals is about 3.7 meV, corresponding to an operating temperature of 43 K. This work reveals a viable approach for realizing QAHE in metal-free graphene nanostructures.