General and transferable tight binding model for two-dimensional Bismuth allotropes

Abstract

Owing to the abundance of allotropes and strong spin-oribital coupling effects (SOC), two-dimensional bismuth materials have attracted great research interest. At present, the most common methods used to calculate the accurate electronic properties accurately are the first-principles calculations based on the hybrid functional HSE06 or GW methods However, HSE06 and GW calculations are hugely time-consuming, especially for large unit-cell systems and high-throughput calculations with a huge number of structures. To study the electronic properties of 2D bismuth allotropes effectively, we propose a general and transferable Slater-Koster tight-binding based on the Bi sp3d5 hybridization, and the set of SK parameters were obtained by fitting the HSE band structures of three Bi allotropes (β-Bi, MBi and αω-Bi). Our results show that our TB model can accurately calculate the electronic properties of different 2D Bi allotropes, including the band structures, orbital projection and topological edge states. Our TB model with excellent transferability and accuracy might facilitate future numerical studies on electronic properties of 2D Bi allotropes with different structures efficiently.