First-principles prediction of quantum anomalous Hall effect in two-dimensional Co ₂Te lattice

The quantum anomalous Hall effect (QAHE) has special quantum properties that are ideal for possible future spintronic devices. However, the experimental realization is rather challenging due to its low Curie temperature and small non-trivial bandgap in two-dimensional (2D) materials. In this paper, we demonstrate through first-principles calculations that monolayer Co ₂Te material is a promising 2D candidate to realize QAHE in practice. Excitingly, through Monte Carlo simulations, it is found that the Curie temperature of single-layer Co ₂Te can reach 573 K. The band crossing at the Fermi level in monolayer Co ₂Te is opened when spin–orbit coupling is considered, which leads to QAHE with a sizable bandgap of E _g = 96 meV, characterized by the non-zero Chern number ( C = 1) and a chiral edge state. Therefore, our findings not only enrich the study of quantum anomalous Hall effect, but also broaden the horizons of the spintronics and topological nanoelectronics applications.