Figure 2

The band structure of Bi₃Te₄I without (a) and with (b) SOC. For (a), the Bi₁-p_z (Bi in TLs) and (Bi in QLs) orbital projected character of bands in the dashed box is shown on the right side. The size of circle denotes the weight of projection. (c) Band dispersion in the vicinity of Γ points showing the Rashba splitting. The parameters of Rashba splitting are also illustrated in the figure. (d) The local band gap at k_z = 0.5 plane (around A points) and k_z = 0.0 plane (around Γ point) as a function of the strength of SOC, where λ_SO = 1 represents the intrinsic value of SOC. (e) Surface energy spectrum of side-cut surface (ac plane) of Bi₃Te₄I.