Quasi-periodic scattering of topological edge states induced by the vacancies in chloridized gallium bismuthide nanoribbons

Abstract

The chloridized gallium bismuthide was predicted to be a two-dimensional topological insulator with large topological band gap. It may be beneficial for achieving the quantum spin Hall effect and its related applications at high temperatures. To better understand the quantum transport in topological nanoribbons, we investigated the effect of vacancy on the quantum transport of topological edge states in the armchair chloridized gallium bismuthide nanoribbons by combining density functional theory and nonequilibrium Green’s function. The results suggest the vacancies at center are more likely to cause the scattering of topological edge states. The average scattering is insensitive to the enlargement of vacancy along the transport direction. More interestingly, the obvious scattering of topological edge states can only be found at some special energies, and these special energies are distributed quasi-periodically. The quasi-periodic scattering may be used as a kind of fingerprint of vacancies. Our studies may be helpful for the application of topological nanoribbons.

SbH Nanoribbons: The Odd–Even Oscillating Band Gap and Resonance Tunneling Behavior

“…Since the rise of graphene, two-dimensional (2D) materials have attracted much attention due to their special physical and chemical properties. − A kind of special 2D material is the well-known 2D topological insulator (TI) which is characterized by the existence of gapless topological edge states. − Theoretically, the topological edge states are protected by the time reversal symmetry and can have no backscattering. − Therefore, the 2D TI has broad application prospects in spintronics, low dissipation nanodevices, and other fields due to its attractive nontrivial topological properties. − …”