The two dimensional local density of states of a Topological Insulator with an edge dislocation

TL;DR

This paper studies how edge dislocations in a topological insulator affect the local density of states and electron propagation, revealing spin-dependent currents and density enhancements detectable by scanning tunneling microscopy.

Contribution

It introduces a theoretical framework for understanding the impact of edge dislocations on the electronic properties of topological insulators, highlighting spin connection effects and density of states modifications.

Findings

Electrons propagate along confined 2D regions and circular contours due to dislocation-induced torsion.

Parity symmetry is violated, leading to measurable in-plane spin currents.

Enhanced tunneling density of states is predicted along specific directions, verifiable by scanning tunneling microscopy.

Abstract

We investigate the effect of a crystal edge dislocation on the metallic surface of a Topological Insulator. The edge dislocation gives rise to torsion which the electrons experience as a spin connection. As a result the electrons propagate along confined two dimensional regions and circular contours. Due to the edge dislocations the parity symmetry is violated resulting in a current measured by the in-plane component of the spin on the surface. The tunneling density of states for Burger vectors in the $y$ direction is maximal along the $x$ direction. The evidence of the enhanced tunneling density of states can be verified with the help of the scanning tunneling technique.