Quantum Anomalous Hall Effect in Magnetic Insulator Heterostructure

On the basis of ab initio Calculations, we predict that a monolayer of Cr-doped (Bi,Sb)(2)Te-3 and GdI2 heterostructure is a quantum anomalous Hall insulator with a nontrivial band gap up to 38 meV. The principle behind our prediction is that the band inversion between two topologically trivial ferromagnetic insulators can result in a nonzero Chem number, which offers a better way to realize the quantum anomalous Hall state without random magnetic doping. In addition, a simple effective model is presented to describe the basic mechanism of spin polarized band inversion in this system. Moreover, we predict that 3D quantum anomalous Hall insulator could-be realized-in (Bi2/3Cr1/3)(2)Te-3 /GdI2 superlattice.