Two-dimensional ferromagnetic Chern insulator: WSe2 monolayer

Abstract

Quantum anomalous Hall (QAH) effect presents a promising platform for next generation nano-electronics due to its dissipationless edge states. Unfortunately, until now, QAH materials suitable for practical applications are rare. Based on the first-principles calculations, we found a novel two-dimensional (2D) QAH insulator: WSe2 monolayer. Both the spin-polarized electronic structure and spin-orbit coupling (SOC) of WSe2 contribute to the QAH effect. When SOC is ignored, the WSe2 monolayer is a spin-polarized Dirac half-metal (DHM). Taking SOC into account, a global band gap about 30 meV is opened and the system behaves as an intrinsic Chern insulator with a Curie temperature of 160 K. The non-trivial properties are proved by the nonzero Chern number, quantized anomalous Hall conductivity, and gapless chiral edge states. We expect the material will become a promising candidate for realizing the QAH effect with higher experimental temperature.