Figure 6: Electronic structure of Bi₁Te₁ along non-high-symmetry lines revealing TCI surface states.

(a) Fermi surface k_||,x versus k_||,y map of a 45 nm in situ transferred film of Bi₁Te₁ obtained with hν=8.4 eV. Red dashed lines mark trajectories along which E_B(k_||,x) spectra in b–g were recorded. Sketch of the surface Brillouin zone is marked for orientation. (b–g) Corresponding experimental spectra as well as spin-polarized DFT calculations (h–m) of a 24QL slab of Bi₁Te₁ with 1QL-terminated surface at (b,h) k_||,y=0.087 Å⁻¹, (c,i) 0.120 Å⁻¹, (d,j) 0.152 Å⁻¹, (e,k) 0.184 Å⁻¹, (f,l) 0.216 Å⁻¹ and (g,m) 0.258 Å⁻¹, respectively. (n) Energy distribution curve along the red dashed line in g.