The built Cu2S/MnSe heterostructures belong to a novel type of Chern insulators, owning unique half-metallic chiral edge states and a very high Fermi velocity (0.87 × 106 m s−1). The full spin-polarization of the edge states is found to be robust against the tuning of chemical potential. This heterostructure has quadratic bands with normal band order, that is, the p/d-like band is below the s-like band. Charge transfer between the Cu2S and the substrate causes the variation of the occupied bands, which together with the spin–orbit coupling triggers the exotic topological state in the system.
- Yang Xue
- Bao Zhao
- Zhongqin Yang
