Interaction-induced crossover between weak anti-localization and weak localization in a disordered InAs/GaSb double quantum well

TL;DR

This study investigates how electron-electron interactions induce a crossover from weak anti-localization to weak localization in a disordered InAs/GaSb quantum well, revealing the dominant phase-breaking mechanism in the system.

Contribution

It demonstrates the interaction-induced crossover between WAL and WL in a 2D quantum well system, highlighting the role of electron-electron interactions in phase coherence.

Findings

Crossover from WAL to WL observed with decreasing carrier density.

Temperature increase induces the same WAL to WL crossover.

Inelastic scattering rate varies linearly with temperature, indicating electron-electron interactions as the main phase-breaking mechanism.

Abstract

We present magneto-transport study in an InAs/GaSb double quantum well structure in the weak localization regime. As the charge carriers are depleted using a top gate electrode, we observe a crossover from weak anti-localization (WAL) to weak localization (WL), when the inelastic phase breaking time decreases below spin-orbit characteristic time as a result of enhanced electron-electron interactions at lower carrier concentrations. The same crossover is observed with increasing temperature. The linear temperature behavior of inelastic scattering rate indicates that the dominant phase breaking mechanism in our 2D system is due to electron-electron interaction.