Non-magnetic defects in the bulk of two-dimensional topological insulators

TL;DR

This paper investigates how non-magnetic defects in 2D topological insulators create bound states with unique properties, revealing a singular energy dependence linked to topological order.

Contribution

It uncovers the existence and characteristics of defect-induced bound states in 2D topological insulators, highlighting a novel singular energy dependence due to topological effects.

Findings

Non-magnetic defects induce electron- and hole-like bound states.

Bound state energies depend singularly on defect potential.

Electron density distribution varies with defect potential sign.

Abstract

We found that non-magnetic defects in two-dimensional topological insulators induce bound states of two kinds for each spin orientation: electron- and hole-like states. Depending on the sign of the defect potential these states can be also of two kinds with different distribution of the electron density. The density has a maximum or minimum in the center. A surprising effect caused by the topological order is a singular dependence of the bound-state energy on the defect potential.