Transport in quantum spin Hall edges in contact to a quantum dot

TL;DR

This paper investigates electron transport in quantum spin Hall edges with an embedded quantum dot, analyzing how Coulomb interactions and spin-flip processes influence transport channels and can be controlled via gate voltage.

Contribution

It introduces a combined approach using non-equilibrium Green functions and quantum Monte Carlo to study the interplay of Coulomb interaction and spin-flip processes in quantum dot transport.

Findings

Transport occurs through different channels depending on U and λ.

The two transport mechanisms can be switched by gate voltage.

The study provides insights into controlling edge transport in quantum spin Hall systems.

Abstract

We study the transport mechanisms taking place in a quantum spin Hall bar with an embedded quantum dot, where electrons localize and experience Coulomb interaction U as well as spin-flip processes {\lambda}. We solve the problem with non-equilibrium Green functions. We focus on the linear response regime and treat the many-body interactions with quantum Monte Carlo. The effects of U and {\lambda} are competitive and the induced transport takes place through different channels. The two mechanisms can be switched by changing the occupation of the dot with a gate voltage.