Interacting electrons in disordered potentials: Conductance versus persistent currents

TL;DR

This paper derives a ground-state property-based expression linking conductance and persistent current in disordered interacting electrons, revealing contrasting effects of interactions on these quantities.

Contribution

It introduces a novel expression connecting conductance to persistent current and compressibility, highlighting their different dependencies on electron-electron interactions.

Findings

Persistent current is enhanced by interactions.

Conductance is suppressed by interactions.

Numerical calculations confirm contrasting behaviors.

Abstract

An expression for the conductance of interacting electrons in the diffusive regime as a function of the ensemble averaged persistent current and the compressibility of the system is presented. This expression involves only ground-state properties of the system. The different dependencies of the conductance and persistent current on the electron-electron interaction strength becomes apparent. The conductance and persistent current of a small system of interacting electrons are calculated numerically and their variation with the strength of the interaction is compared. It is found that while the persistent current is enhanced by interactions, the conductance is suppressed.