Abstract
We theoretically propose that the van der Waals layered ternary transition metal chalcogenide V₂ MX₄ (M= W, Mo; X= S, Se) is a new family of quantum anomalous Hall insulators with sizable bulk gap and Chern number C=-1. The large topological gap originates from the \emph{deep} band inversion between spin up bands contributed by d_xz,d_yz orbitals of V and spin down band from d_z² orbital of M at Fermi level. Remarkably, the Curie temperature of monolayer V₂ MX₄ is predicted to be much higher than that of monolayer MnBi₂Te₄. Furthermore, the thickness dependence of the Chern number for few multilayers shows interesting oscillating behavior. The general physics from the d-orbitals here applies to a large class of ternary transition metal chalcogenide such as Ti₂WX₄ with the space group P-42m. These interesting predictions, if realized experimentally, could greatly promote the research and application of topological quantum physics.