We have studied the topological insulator Bi2Te3(111) by means of helium atom scattering. The average electron-phonon coupling λ of Bi2Te3(111) is determined by adapting a recently developed quantum-theoretical derivation of the helium scattering probabilities to the case of degenerate semiconductors. Based on the Debye-Waller attenuation of the elastic diffraction peaks of Bi2Te3(111), measured at surface temperatures between 110\mboxK and 355\mboxK, we find λ to be in the range of 0.04−0.11. This method allows to extract a correctly averaged λ and to address the discrepancy between previous studies. The relatively modest value of λ is not surprising even though some individual phonons may provide a larger electron-phonon interaction. Furthermore, the surface Debye temperature of Bi2Te3(111) is determined as ΘD=(81±6)\mboxK. The electronic surface corrugation was analysed based on close-coupling calculations. By using a corrugated Morse potential a peak-to-peak corrugation of 9% of the lattice constant is obtained.
@article{arxiv.1704.07416,
title = {Electron-Phonon Coupling and Surface Debye Temperature of Bi$_2$Te$_3$(111) from Helium Atom Scattering},
author = {Anton Tamtögl and Patrick Kraus and Nadav Avidor and Martin Bremholm and Ellen M. J. Hedegaard and Bo B. Iversen and Marco Bianchi and Philip Hofmann and John Ellis and William Allison and Giorgio Benedek and Wolfgang E. Ernst},
journal= {arXiv preprint arXiv:1704.07416},
year = {2017}
}