Strong Electron-Electron Interactions of a Tomonaga--Luttinger Liquid Observed in InAs Quantum Wires

TL;DR

This paper demonstrates strong electron-electron interactions in InAs quantum wires, exhibiting Tomonaga-Luttinger liquid behavior, with implications for quantum devices combining strong interactions and spin-orbit coupling.

Contribution

It provides experimental evidence of Tomonaga-Luttinger liquid behavior in InAs wires and quantifies the interaction strength, highlighting the role of spin-orbit interactions.

Findings

Current follows universal scaling of a Tomonaga-Luttinger liquid.

Strong electron-electron interactions increase with depletion.

Spin-orbit interactions cause minor modifications to the interaction parameter.

Abstract

We report strong electron-electron interactions in quantum wires etched from an InAs quantum well, a material known to have strong spin-orbit interactions. We find that the current through the wires as a function of the bias voltage and temperature follows the universal scaling behavior of a Tomonaga--Luttinger liquid. Using a universal scaling formula, we extract the interaction parameter and find strong electron-electron interactions, increasing as the wires become more depleted. We establish theoretically that spin-orbit interactions cause only minor modifications of the interaction parameter in this regime, indicating that genuinely strong electron-electron interactions are indeed achieved in the device. Our results suggest that etched InAs wires provide a platform with both strong electron-electron and strong spin-orbit interactions.