Observation of a Helical Luttinger-Liquid in InAs/GaSb Quantum Spin Hall Edges

TL;DR

This paper reports the experimental observation of a helical Luttinger-liquid in InAs/GaSb quantum spin Hall insulator edges, demonstrating strong electron interactions and tunable parameters, providing a platform for studying correlated 1D systems.

Contribution

First experimental detection of a tunable helical Luttinger-liquid in InAs/GaSb quantum spin Hall edges, highlighting electron-electron interactions and controllable Luttinger parameters.

Findings

Conductance suppression at low temperature and bias

Power-law dependence of conductance on temperature and bias

Tunable Luttinger parameter via gate control

Abstract

We report on the observation of a helical Luttinger-liquid in the edge of InAs/GaSb quantum spin Hall insulator, which shows characteristic suppression of conductance at low temperature and low bias voltage. Moreover, the conductance shows power-law behavior as a function of temperature and bias voltage. The results underscore the strong electron-electron interaction effect in transport of InAs/GaSb edge states. Because of the fact that the Fermi velocity of the edge modes is controlled by gates, the Luttinger parameter can be fine tuned. Realization of a tunable Luttinger-liquid offers a one-dimensional model system for future studies of predicted correlation effects.