Conductance through a One-Dimensional Correlated System: Relation to Persistent Currents and Role of the Contacts

TL;DR

This paper explores how conductance in a one-dimensional correlated electron system relates to persistent currents in a ring setup, revealing that interactions can enhance conductance especially in disordered samples, and introduces a scaling law for conductance determination.

Contribution

It establishes a method to determine conductance from persistent current measurements using a scaling law, highlighting the role of contacts and interactions in disordered systems.

Findings

Conductance can be inferred from persistent current measurements.

Interactions enhance conductance in strongly disordered samples.

A scaling law allows extrapolation to intrinsic conductance values.

Abstract

Based on a recent proposal [O.P. Sushkov, Phys. Rev. B 64, 155319 (2001)], we relate the quantum conductance through a sample in which electrons are strongly correlated to the persistent current of a large ring, composed of the sample and a non-interacting lead. A scaling law in the lead length allows to extrapolate to a well-defined value of the conductance, depending only on intrinsic properties of the sample and the nature of the contacts between the sample and the lead. For strongly disordered samples, the conductance is found to be enhanced by the interaction.