Persistence of surface states despite impurities in the surface of topological insulators
Department of Physics, Chonnam National University - Gwangju 500-757, Korea
2 Pohang Accelerator Laboratory and Department of Physics, Pohang University of Science and Technology - Pohang 790-784, Korea
Accepted: 23 September 2011
We have experimentally demonstrated the robustness and immunity of the surface states to surface impurities and disorder in topological insulator (TI) Bi0.9Sb0.1 in comparison with those of semi-metallic Sb(111) surface by measuring the scattering rates of the quasiparticles (QP) via angle-resolved photoemission spectroscopy. The surface impurities on TIs increase the scattering rate of the QPs but their effects are extrinsic and limited regardless of their magnetic properties, while in the semimetallic Sb case they open new scattering channels making the surface states fragile.
PACS: 73.20.-r – Electron states at surfaces and interfaces / 79.60.-i – Photoemission and photoelectron spectra / 71.20.-b – Electron density of states and band structure of crystalline solids
© EPLA, 2011