Conductance of fractional Luttinger liquids at finite temperatures

TL;DR

This paper investigates how fractional conductance in quantum wires with spin-orbit interaction and magnetic fields varies with temperature, considering effects of finite length, contacts, and chemical potential shifts using bosonization techniques.

Contribution

It introduces a combined bosonization approach to analyze fractional conductance in quantum wires with partial spectral gaps under magnetic fields.

Findings

Low-temperature fractional conductance is sensitive to wire length and contact properties.

Finite temperature effects modify the conductance behavior near the partial gap.

Internal resistivity arises from dissipative coupling between gapped and gapless modes.

Abstract

We study the electrical conductance in single-mode quantum wires with Rashba spin-orbit interaction subjected to externally applied magnetic fields in the regime in which the ratio of spin-orbit momentum to the Fermi momentum is close to an odd integer, so that a combined effect of multi-electron interaction and applied magnetic field leads to a partial gap in the spectrum. We study how this partial gap manifests itself in the temperature dependence of the fractional conductance of the quantum wire. We use two complementing techniques based on bosonization: refermionization of the model at a particular value of the interaction parameter and a semiclassical approach within a dilute soliton gas approximation of the functional integral. We show how the low-temperature fractional conductance can be affected by the finite length of the wire, by the properties of the contacts, and by a shift of the chemical potential, which takes the system away from the resonance condition. We also predict an internal resistivity caused by a dissipative coupling between gapped and gapless modes.