Near room-temperature high Chern-number quantum anomalous Hall effect in ferromagnet NiSbO3

Abstract

The quantum anomalous Hall effect (QAHE), which exhibits dissipationless chiral edge states without external magnetic fields, has garnered considerable attention in condensed matter physics. Here, we propose a near room-temperature high Chern-number QAHE in NiSbO3. Our first-principles calculations reveal that monolayer ferromagnetic NiSbO3 is energetically favored and the Curie temperature is about 291 K. The half-filled state of degenerate dxz/dyz orbitals for the spin-up channel provide a linearly crossing point at the Fermi level, which can be gapped by the spin orbital coupling. Remarkably, the obtained Chern number C is as high as 3. QAHE of C = 6 is obtained in the bilayer, benefiting from interlayer ferromagnetic coupling. Moreover, an electric field is applied along the z direction, the easy magnetization axis changes from in-plane to out-of-plane direction. At the same time, the bandgap increases with the electric field, which facilitates the experimental observation of QAHE. Our work offers a promising candidate for applications of multiple dissipationless chiral edges in topological quantum devices.