Response of the topological surface state to surface disorder in TlBiSe${}_2$

Abstract

Through a combination of experimental techniques we show that the topmost layer of the topo- logical insulator TlBiSe${}_2$ as prepared by cleavage is formed by irregularly shaped Tl islands at cryogenic temperatures and by mobile Tl atoms at room temperature. No trivial surface states are observed in photoemission at low temperatures, which suggests that these islands can not be re- garded as a clear surface termination. The topological surface state is, however, clearly resolved in photoemission experiments. This is interpreted as a direct evidence of its topological self-protection and shows the robust nature of the Dirac cone like surface state. Our results can also help explain the apparent mass acquisition in S-doped TlBiSe${}_2$.

16 pages, 5 figures

References in corpus (5)

• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Topological Surface States Protected From Backscattering by Chiral Spin Texture
• Coexistence of the topological state and a two-dimensional electron gas on the surface of Bi2Se3
• Unexpected mass acquisition of Dirac fermions at the quantum phase transition of a topological insulator
• The fate of topological-insulator surface states under strong disorder