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 image point. We find that the topological nature of the surface state remains robust with different terminations of the surface.