We investigated the electronic properties of the topological insulator Bi2Te3 by scanning tunneling microscopy and spectroscopy at low temperature. We obtained high-resolution quasiparticle interference data of the topological surface Dirac electrons at different energies. Spin-selective joint density of states calculations were performed for surface and bulk electronic states to interpret the observed quasiparticle interference data. The topological properties of our crystals are demonstrated by the absence of backscattering along with the linear energy dispersion of the dominant scattering vector. In addition, we detect non-dispersive scattering modes which we associate with bulk-surface scattering and, thus, allow an approximate identification of the bulk energy gap range based on our quasiparticle interference data. Measurements of differential conductance maps in magnetic fields up to 15 T have been carried out, but no strong modifications could be observed.
@article{arxiv.2409.04294,
title = {Bulk and surface electron scattering in disordered Bi$_{2}$Te$_{3}$ probed by quasiparticle interference},
author = {Vladislav Nagorkin and Sebastian Schimmel and Paul Gebauer and Anna Isaeva and Danny Baumann and Andreas Koitzsch and Bernd Büchner and Christian Hess},
journal= {arXiv preprint arXiv:2409.04294},
year = {2025}
}