Luttinger liquid behavior in weakly disordered quantum wires

TL;DR

This study investigates the temperature-dependent conductance in GaAs quantum wires, confirming Luttinger liquid behavior in weakly disordered samples and highlighting the limitations of perturbation theory in more disordered cases.

Contribution

It provides experimental validation of Luttinger liquid theory in weakly disordered quantum wires and identifies the impact of disorder level on conductance behavior.

Findings

Weak disorder samples have g=0.66, matching theoretical expectations.

Higher disorder leads to stronger temperature dependence and breakdown of perturbation theory.

Perturbation theory underestimates the interaction parameter g in disordered samples.

Abstract

We have measured the temperature dependence of the conductance in long V-groove quantum wires (QWRs) fabricated in GaAs/AlGaAs heterostructures. Our data is consistent with recent theories developed within the framework of the Luttinger liquid model, in the limit of weakly disordered wires. We show that for the relatively small amount of disorder in our QWRs, the value of the interaction parameter g is g=0.66, which is the expected value for GaAs. However, samples with a higher level of disorder show conductance with stronger temperature dependence, which does not allow their treatment in the framework of perturbation theory. Trying to fit such data with perturbation-theory models leads inevitably to wrong (lower) values of g.