Electric Field Dependence of Topological Edge States in One-Bilayer Bi(111): A First-Principles Study

Abstract

We investigate the effect of the electric field on the edge states in one-bilayer Bi(111) by first-principles calculations. We calculate the band structures of armchair and zigzag Bi nanoribbons. With increasing strength of the electric field E > 2.1 V/Å, the armchair nanoribbon shows a topological phase transition from non-trivial metallic edge states to insulating edge states. However, under the same conditions, the zigzag nanoribbon shows a topological phase transition from non-trivial metallic edge states to trivial metallic edge states. We expect that these findings will contribute to the development of, e.g., spin current switches for use in next-generation devices. [DOI: 10.1380/ejssnt.2018.427]