Spin-charge separation in transport through Luttinger liquid rings

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 ringlike 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 that is governed by the interaction dependent velocities. Our work extends an earlier study that 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.