Through a combination of experimental techniques we show that the topmost layer of the topo- logical insulator TlBiSe2 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 TlBiSe2.
@article{arxiv.1502.01112,
title = {Response of the topological surface state to surface disorder in TlBiSe$_2$},
author = {Florian Pielmeier and Gabriel Landolt and Bartosz Slomski and Stefan Muff and Julian Berwanger and Andreas Eich and Alexander A. Khajetoorians and Jens Wiebe and Ziya S. Aliev and Mahammad B. Babanly and Roland Wiesendanger and Jürg Osterwalder and Evgeniy V. Chulkov and Franz J. Giessibl and J. Hugo Dil},
journal= {arXiv preprint arXiv:1502.01112},
year = {2015}
}