Quasistationary states in a quantum dot formed at the edge of a topological insulator by magnetic barriers with finite transparency

TL;DR

This paper models quasistationary states in edge channels of a topological insulator with magnetic barriers, providing analytical and numerical insights into their lifetimes for potential quantum dot applications.

Contribution

It introduces a new model for quasistationary states in topological insulator edge states with magnetic barriers, including analytical and numerical lifetime calculations.

Findings

Analytical and numerical lifetimes of quasistationary states are obtained.

Magnetic barriers can create quantum dots with controllable state lifetimes.

Results guide the design of magnetic barriers for quantum manipulation.

Abstract

A model of quasistationary states is constructed for the one-dimensional edge states propagating along the edge of a two-dimensional topological insulator based on HgTe/CdTe quantum well in the presence of magnetic barriers with finite transparency. The lifetimes of these quasistationary states are found analytically and numerically via different approaches including the solution of the stationary Schroedinger equation with complex energy and the solution of the transmission problem for a double barrier structure. The results can serve as a guide for determining the parameters of magnetic barriers creating the quantum dots where the lifetimes for the broadened discrete levels are long enough for manipulation with their occupation numbers by external fields.