Figure 1: Electronic structure of one-bilayer Bi on TlBiS2.
From: Topological proximity effect in a topological insulator hybrid
(a) Crystal structure of TlBi(S,Se)2. (b) Surface and bulk Brillouin zone (SBZ and BBZ respectively) of TlBiX2 (X=S, Se). (c,d) Comparison of the near-EF ARPES intensity between 1BL Bi/TlBiS2 and pristine TlBiS2 measured along the 
(kx) cut with the He-I photons (hν=21.218 eV) at T=30 K. CB and VB denote the bulk conduction and valence bands of TlBiS2, respectively. (e,f) ARPES intensity around the 
point measured with the Xe-I photons (hν=8.437 eV) for 1BL Bi on nontopological TlBiS2 and on topological TlBiSe2, respectively. Calculated band structure for free-standing 1BL Bi is overlaid in e with an upward energy shift of ~0.4 eV, which takes into account the heavily hole-doped nature of the Bi film due to charge transfer to the TlBiX2 substrate.
