Quantum corrections to the conductivity and Hall coefficient of a two-dimensional electron gas in a dirty AlGaAs/GaAs/AlGaAs quantum well: from the diffusive to the ballistic regime

TL;DR

This study experimentally investigates quantum corrections to conductivity and Hall effect in a low mobility two-dimensional electron gas across diffusive and ballistic regimes, confirming theoretical predictions over a wide temperature range.

Contribution

It provides the first comprehensive experimental validation of interaction-induced quantum corrections across the diffusive to ballistic transition in a 2D electron gas.

Findings

Quantitative agreement with theoretical models

Observation of crossover between diffusive and ballistic regimes

Validation of interaction correction theories for conductivity and Hall effect

Abstract

We report an experimental study of quantum conductivity corrections in a low mobility, high density two-dimensional electron gas in a AlGaAs/GaAs/AlGaAs quantum well in a wide temperature range (1.5K - 110K). This temperature range covers both the diffusive and the ballistic interaction regimes for our samples. It has been therefore possible to study the crossover between these regimes for both the longitudinal conductivity and the Hall effect. We perform a parameter free comparison of our experimental data for the longitudinal conductivity at zero magnetic field, the Hall coefficient, and the magnetoresistivity to the recent theories of interaction-induced corrections to the transport coefficients. A quantitative agreement between these theories and our experimental results has been found.