High Curie temperature Chern insulator and spin-gapless semiconducting ferromagnetic h-CrC monolayer: A first-principles study

Abstract

Based on first-principles calculations, we predict that the 2D h-CrC is an intrinsic ferromagnetic spin-gapless semiconducting material with 100 % spin polarization and high carrier mobility. The electronic structure of h-CrC monolayer is also calculated by using the Hybrid functionals and analyzed by the tight-binding model. Compared with the calculated results of the Hybrid functional theory, the tight-binding band structure is perfectly consistent with the results of the density functional theory. In addition, by using the Monte Carlo simulations we estimate that the Curie temperature of h-CrC monolayer can be as high as 600 K. The dynamic and thermal stability at room temperature ensures its experimental feasibility. However, when considering spin–orbit coupling, the spin-gapless state of the h-CrC monolayer is opened a ∼22 meV non-trivial band gap, which leads to the quantum anomalous Hall effect. We also determine the influence of the energy band and QAH state of h-CrC monolayer on the correlation of Cr-3d electrons and SOC interaction. Moreover, the band gap of h-CrC can be effectively controlled by constructing the heterojunctions and quantum wells while retaining the quantum Hall insulator, which provides an ideal candidate material for exploring and designing quantum transport devices with high Curie temperature.