We study theoretically by a quantum-mechanical approach the general scattering problem of a straight step defect on the surface of topological insulator Bi2Te3 with strong warping effect. At high energy where the warping effect is large, an incident electron on a step defect running along Γ−M direction may exhibit perfect transmission whereas on a defect running along Γ−K direction has a finite probability to be reflected and may even exhibit resonant total reflection. Transmission properties in the latter case are also very sensitive to whether there is particle-hole symmetry. The predicted Friedel oscillations and the power-law decaying behavior of the local density of states (LDOS) near the defect are in good agreement with recent scanning tunneling microscope experiments on Bi2Te3. The high-energy LDOS of the surface states is also found to show the multi-periodic Friedel oscillations, caused by competing characteristic scattering processes.
@article{arxiv.1204.6363,
title = {Surface states scattering from a step defect in topological insulator Bi_{2}Te_{3}},
author = {Jin An and C. S. Ting},
journal= {arXiv preprint arXiv:1204.6363},
year = {2012}
}