Magnetoresistance of a 2D electron gas caused by electron interactions in the transition from the diffusive to the ballistic regime

TL;DR

This study investigates how electron-electron interactions influence magnetoresistance in a high-mobility 2D electron gas during the transition from diffusive to ballistic regimes, revealing a parabolic negative magnetoresistance in strong magnetic fields.

Contribution

It provides experimental evidence and analysis of interaction-induced magnetoresistance in the transition regime, comparing results with new theoretical predictions.

Findings

Observation of parabolic negative magnetoresistance caused by electron interactions.

Extraction of interaction correction to conductivity from temperature dependence.

Agreement with new theoretical models of interaction-induced magnetoresistance.

Abstract

On a high-mobility 2D electron gas we have observed, in strong magnetic fields (omega_{c} tau > 1), a parabolic negative magnetoresistance caused by electron-electron interactions in the regime of k_{B} T tau / hbar ~ 1, which is the transition from the diffusive to the ballistic regime. From the temperature dependence of this magnetoresistance the interaction correction to the conductivity delta sigma_{xx}^{ee}(T) is obtained in the situation of a long-range fluctuation potential and strong magnetic field. The results are compared with predictions of the new theory of interaction-induced magnetoresistance.