Bulk and surface electronic structure of SnBi4Te7 topological insulator

Using density functional theory with the spin-orbit coupling included we analyze the bulk and surface electronic structure of SnBi4Te7 ternary compound. It was revealed that this material is a strong topological insulator with a bulk band gap of about 100 meV and a robust surface state around the Γ¯ point. We find that the topological nature of the surface state remains robust with different terminations of the surface.

► Study of the bulk and surface electronic structure of SnBi4Te7. ► By means of DFT and introducing the spin-orbit interaction we find the inverted bands at the bulk Γ point. ► We study the surface of this compound with 2 different terminations. ► We find a robust topological surface state in both cases but with different localization.