Quantum anomalous Hall conductivity in 3D magnetic topological insulator/normal insulator heterostructures

Today, searching for materials hosting quantum anomalous Hall effect (QAHE) at high temperature and with long conductivity plateau is an important issue for next generation spintronic applications at nanoscale. In this article, we discuss a quantized spin Hall response in heterostructures composed of a three-dimensional topological insulator (TI) film and a ferromagnetic normal insulator (FMNI). The magnetic proximity effect at the TI/FMNI interface provides exchange splitting of the topological states in the TI film. We predict analytically that the FMNI/TI/FMNI trilayer can be driven into the QAHE state either from the topologically trivial state or the quantum spin Hall state, depending on the TI film thickness and the interface potential. We calculate the corresponding phase diagram of the FMNI/TI/FMNI trilayer. Our results provide a useful guide to realize the QAHE regime in the TI/FMNI heterostructures.This work was supported by the Grant No. 17-12-01345 of the Russian Science Foundation (in the part of analytic investigation of the electronic properties of FMNI/TI heterostructures). We also acknowledge the support from the Basque Country Government, Departamento de Educación, Universidades e Investigación (Grant No. IT-756-13), the Spanish Ministerio de Ciencia e Innovación (Grant No. FIS2016-75862-P) (in the part of calculation of anomalous Hall response), the Tomsk State University Academic D.I. Mendeleev Fund Program (Grant No. 8.1.05.2015), Saint Petersburg State University (Grant No. 15.61.202.2015) (in the part of numeric calculation of the phase diagram).Peer reviewe