Measurement of an Exceptionally Weak Electron-Phonon Coupling on the   Surface of the Topological Insulator Bi$_2$Se$_3$ Using Angle-Resolved   Photoemission Spectroscopy
  Gapless surface states on topological insulators are protected from elastic scattering on non-magnetic impurities which makes them promising candidates for low-power electronic applications. However, for wide-spread applications, these states should have to remain coherent at ambient temperatures. Here, we studied temperature dependence of the electronic structure and the scattering rates on the surface of a model topological insulator, Bi$_2$Se$_3$, by high resolution angle-resolved photoemission spectroscopy. We found an extremely weak broadening of the topological surface state with temperature and no anomalies in the state's dispersion, indicating exceptionally weak electron-phonon coupling. Our results demonstrate that the topological surface state is protected not only from elastic scattering on impurities, but also from scattering on low-energy phonons, suggesting that topological insulators could serve as a basis for room temperature electronic devices. 
Z.-H. Pan, A. V. Fedorov, D. Gardner, Y. S. Lee, S. Chu and T. Valla
cond-mat.str-el cond-mat.mtrl-sci