Electronic Structures and Surface States of Topological Insulator Bi${}_{1-x}$Sb${}_x$

Abstract

We investigate the electronic structures of the alloyed Bi${}_{1-x}$Sb${}_x$ compounds based on first-principle calculations including spin-orbit coupling (SOC), and calculate the surface states of semi-infinite systems using maximally localized Wannier function (MLWF). From the calculated results, we analyze the topological nature of Bi${}_{1-x}$Sb${}_x$, and found the followings: (1) pure Bi crystal is topologically trivial; (2) topologically non-trivial phase can be realized by reducing the strength of SOC via Sb doping; (3) the indirect bulk band gap, which is crucial to realize the true bulk insulating phase, can be enhanced by uniaxial pressure along c axis. (4) The calculated surface states can be compared with experimental results, which confirms the topological nature; (5) We predict the spin-resolved Fermi surfaces and showed the vortex structures, which should be examined by future experiments.

8 pages, 11 figures

References in corpus (5)

• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• First direct observation of Spin-textures in Topological Insulators : Spin-resolved ARPES as a probe of topological quantum spin Hall effect and Berry's phase
• Strong spin-orbit splitting on Bi surfaces

Cited by in corpus (1)

• Topological Surface States Protected From Backscattering by Chiral Spin Texture