Quasiparticle Interference on the Surface of the Topological Insulator Bi$_2$Te$_3$

TL;DR

This study uses T-matrix formalism to analyze quasiparticle interference on Bi$_2$Te$_3$ surface states, revealing scattering behaviors influenced by spin configurations and matching experimental observations.

Contribution

It introduces a detailed theoretical analysis of quasiparticle scattering considering spin-orbit effects on topological insulator surfaces.

Findings

Backscatterings are forbidden by time-reversal symmetry.

Allowed scatterings depend on spin configurations.

The characteristic scattering wavevectors agree with experiments.

Abstract

The quasiparticle interference of the spectroscopic imaging scanning tunneling microscopy has been investigated for the surface states of the large gap topological insulator Bi$_2$Te$_3$ through the T-matrix formalism. Both the scalar potential scattering and the spin-orbit scattering on the warped hexagonal isoenergy contour are considered. While backscatterings are forbidden by time-reversal symmetry, other scatterings are allowed and exhibit strong dependence on the spin configurations of the eigenfunctions at k points over the isoenergy contour. The characteristic scattering wavevectors found in our analysis agree well with recent experiment results.