Suppression of the Coulomb interaction contribution to the conductance by a parallel magnetic field

TL;DR

This paper investigates how a parallel magnetic field affects the Coulomb interaction contribution to conductance in a disordered 2D electron gas, revealing suppression contrary to theoretical expectations and observing large-scale magnetoresistance fluctuations.

Contribution

It provides experimental evidence that a parallel magnetic field suppresses Coulomb interaction effects in 2D conductance, challenging existing theoretical predictions.

Findings

Coulomb interaction contribution quantified as dGeei=-0.3 e^2/h.

Parallel magnetic field suppresses Coulomb interaction contribution.

Reproducible magnetoresistance fluctuations observed over large magnetic field scales.

Abstract

The Coulomb interaction contribution to the conductance is investigated in a phase-coherent disordered 2-dimensional electron gas, which resistance can be varied by an overall gate electrode. Its magnitude of dGeei=-0.3 e^2/h is obtained by applying a bias voltage to suppress the Coulomb anomaly. In contrast to theoretical predictions, dGeei is suppressed by a parallel magnetic field. The zero-bias magnetoresistance exhibits reproducible fluctuations in perpendicular magnetic fields on a field scale much larger than that expected for universal conductance fluctuations, which might be attributed to fluctuations in the Coulomb interaction contribution.