Field-controlled quantum anomalous Hall effect in electron-doped CrSiTe${}_3$ monolayer: a first-principles prediction

Abstract

We report Chern insulating phases emerging from a single layer of layered chalcogenide CrSiTe${}_3$, a transition metal trichacogenides (TMTC) material, in the presence of charge doping. Due to strong hybridization with Te $p$ orbitals, the spin-orbit coupling effect opens a finite band gap, leading to a nontrivial topology of the Cr $e_{\mathrm{g}}$ conduction band manifold with higher Chern numbers. Our calculations show that quantum anomalous Hall effects can be realized by adding one electron in a formula unit cell of Cr${}_2$Si${}_2$Te${}_6$, equivalent to electron doping by 2.36$\times$10${}^{14}$ cm${}^{-2}$ carrier density. Furthermore, the doping-induced anomalous Hall conductivity can be controlled by an external magnetic field via spin-orientation-dependent tuning of the spin-orbit coupling. In addition, we find distinct quantum anomalous Hall phases employing tight-binding model analysis, suggesting that CrSiTe${}_3$ can be a fascinating new platform to realize Chern insulating systems with higher Chern numbers.

9 pages, 8 figures, and additional supplementary information