Room-Temperature Quantum Anomalous Hall Effect in Single-Layer CrP₂S₆

Abstract

The quantum anomalous Hall (QAH) effect is a fascinating quantum phenomenon characterized by a nonzero Chern number defined in the bulk and chiral edge states in the boundary. Up to now, only one magnetically doped topological insulator, suffering from a small bulk band gap, is confirmed to host the QAH effect experimentally. Here, through first-principles calculations, we propose a novel QAH insulator in single-layer (SL) CrP₂S₆. The nontrivial topology in SL CrP₂S₆, identified with the nonzero Chern number (C = −1) and chiral edge states, harbors a nontrivial band gap of 53 meV. Meanwhile, using Monte Carlo simulations, the Curie temperature Tc for its ferromagnetic order is estimated to be 350 K, which is above room temperature and comparable with most of the previously reported two-dimensional ferromagnetic semiconductors. Our findings thus present a feasible platform for achieving the QAH effect at room temperature.