First-principles calculations of the surface states of doped and alloyed topological materials via band unfolding method

One of the most remarkable characteristics of topological materials is that they have special surface states, which are determined by the topological properties of their bulk materials. Angle resolved photoemission spectroscopy (ARPES) is a powerful tool to explore surface states, which allows to further investigate the topological phase transitions. However, it is very difficult to compare the first-principles calculated band structures to the ARPES results, when the systems are doped or alloyed, because the band structures are heavily folded. We develop an efficient band unfolding method based on numerical atomic orbitals (NAOs). We apply this method to study the surface states of the non-magnetically and magnetically doped topological insulators Bi2Se3 and the topological crystalline insulators Pb1-x SnxTe.

Automated summary

One of the remarkable features of topological materials is the presence of special surface states, which can be explored using ARPES. However, comparing calculated band structures with experimental results is difficult when the systems are doped or alloyed. To solve this problem, we have developed an efficient band unfolding method based on NAOs, which we have applied to study the surface states of non-magnetic and magnetic doped topological insulators and topological crystalline insulators.