Figure 2

QPI patterns on the (Bi_0.45Sb_0.55)₂Te₃ films surface.

(a) STM image of the (Bi_0.44Sb₅₆)₂Te₃ surface (50 nm × 50 nm). The inset shows the FFT result of (a) and the first Brillouin Zone is added. (b1–b12) dI/dV maps of the same area as (a) at different tip bias. The values of tip bias are shown in figures. The scanning current was 380 pA. Each map has 256 × 256 pixels. The dash lines in (a) and (b1–b12) are marks to indicate the relative positions in STM images. (c1–c12) FFT results of the dI/dV maps (b1–b12) respectively. The first Brillouin Zone of (Bi_0.44Sb₅₆)₂Te₃ surface is superimposed in (C4) and (C9) to show the directions of quasipartilce scattering.