We present angle resolved photoemission experiments and scanning tunneling spectroscopy results on the doped topological insulator Cu0.2Bi2Te3. Quasi-particle interference (QPI) measurements, based on high resolution conductance maps of the local density of states show that there are three distinct energy windows for quasi-particle scattering. Using a model Hamiltonian for this system two new scattering channels are identified: the first between the surface states and the conduction band and the second between conduction band states. We also observe that the real space density modulation has a predominant three-fold symmetry, which rules out a simple, isotropic impurity potential. We obtain agreement between experiment and theory by considering a modified scattering potential that is consistent with having mostly Bi-Te anti-site defects as scatterers.
@article{arxiv.1110.4406,
title = {Multiband quasiparticle interference in the topological insulator Cu_(x)Bi_(2)Te_(3)},
author = {E. van Heumen and G. A. R. van Dalum and J. Kaas and N. de Jong and J. Oen and Y. K. Huang and A. K. Mitchell and L. Fritz and M. S. Golden},
journal= {arXiv preprint arXiv:1110.4406},
year = {2019}
}
Comments
Updated the discussion of results. New model for impurity scattering added to the discussion. Corrected labelling of some figures