Study of Spin-Orbit Coupling Effect on Bismuth (111) Bilayer
M. Bieniek, T. Woźniak and P. Potasz
Department of Theoretical Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, PL-50-370 Wrocław, Poland
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Band inversion: process in Bi(111) bilayer is studied using many-orbital tight-binding model, supported by the density-functional theory calculations, with a controllable spin-orbit coupling constant in tight-binding model. This effect is important in order to verify a topological nature of this material. We show that after closing of the energy gap leading to crossing of the valence and conduction bands, the second band inversion occurs within a valence band. We analyze orbital composition and spin textures of bands within different regimes. Around a Γ point, all spins align in one direction before the first band inversion. Moreover, a change of signs for some spin components after a band inversion is noticed. After the second band inversion, a significant change of orbital contribution of the top of the valence band is observed.

DOI: 10.12693/APhysPolA.130.609
PACS numbers: 73.22.Dj, 74.20.Pq