Tunneling between edge states in a quantum spin Hall system

TL;DR

This paper investigates spin tunneling in a quantum spin Hall device with a point contact, revealing how electron interactions influence tunneling current and conductance scaling with voltage and temperature.

Contribution

It introduces a model for spin tunneling in QSH systems and analyzes the nonlinear effects of electron-electron interactions on transport properties.

Findings

Tunneling current scales nonlinearly with voltage and temperature.

Differential conductance exhibits interaction-dependent scaling.

The model predicts measurable signatures of spin tunneling in experiments.

Abstract

We analyze a quantum spin Hall (QSH) device with a point contact connecting two of its edges. The contact supports a net spin tunneling current that can be probed experimentally via a two-terminal resistance measurement. We find that the low-bias tunneling current and the differential conductance exhibit scaling with voltage and temperature that depend nonlinearly on the strength of the electron-electron interaction.