Spin-charge separation in transport through Luttinger liquid rings

TL;DR

This paper explores how different velocities in Luttinger liquids influence transport in ring conductors, revealing interaction-dependent flux conductance features and extending previous specific-case analyses.

Contribution

It generalizes earlier work by analyzing generic repulsive interactions and clarifies the validity of key approximations in Luttinger liquid transport models.

Findings

Flux dependence of conductance shows dips governed by interaction velocities.

Number of dips relates to the ratio of charge and spin velocities.

The study extends understanding beyond specific interaction parameter choices.

Abstract

We investigate how the different velocities characterizing the low-energy spectral properties and the low-temperature thermodynamics of one-dimensional correlated electron systems (Luttinger liquids) affect the transport properties of ring-like conductors. The Luttinger liquid ring is coupled to two noninteracting leads and pierced by a magnetic flux. We study the flux dependence of the linear conductance. It shows a dip structure which is governed by the interaction dependent velocities. Our work extends an earlier study which was restricted to rather specific choices of the interaction parameters. We show that for generic repulsive two-particle interactions the number of dips can be estimated from the ratio of the charge current velocity and the spin velocity. In addition, we clarify the range of validity of the central approximation underlying the earlier study.