Spin direction dependent quantum anomalous Hall effect in two-dimensional ferromagnetic materials

Abstract

We propose a scheme for realizing spin-direction dependent Quantum Anomalous Hall Effect (QAHE) driven by spin-orbit couplings (SOC) strength in two-dimensional (2D) materials. Based on the sp 3 tight-binding (TB) model, we find that these systems can harbor QAHE with out-of-plane and in-plane magnetization for the weak and strong SOC, respectively, in which the mechanism of quantum transition is mainly driven by the band inversion of p x,y /p z orbitals. As a concrete example, based on first-principles calculations, we realize a real material of monolayer 1T-SnN2/PbN2 to exhibit QAHE with in-plane/out-of-plane magnetization characterized by the nonzero Chern number C and topological edge states. These findings provide useful guidance for the pursuit of spin-direction-dependent QAHE and hence stimulate immediate experimental interest.