Finite-temperature conductance of strongly interacting quantum wire with a nuclear spin order

TL;DR

This paper investigates how the electrical conductance of a strongly interacting quantum wire with nuclear spin order varies with temperature, revealing a transition from a partially gapped state to a fully conducting state.

Contribution

It introduces a bosonization-based model to describe temperature-dependent conductance changes in quantum wires with nuclear spin order, linking theory with recent experimental observations.

Findings

Conductance increases from e^2/h to 2e^2/h as temperature rises.

A partial gap in the electron spectrum causes a resistivity due to kink interactions.

The model aligns well with experimental data on GaAs quantum wires.

Abstract

We study the temperature dependence of the electrical conductance of a clean strongly interacting quantum wire in the presence of a helical nuclear spin order. The nuclear spin helix opens a temperature-dependent partial gap in the electron spectrum. Using a bosonization framework we describe the gapped electron modes by sine-Gordon-like kinks. We predict an internal resistivity caused by an Ohmic-like friction these kinks experience via interacting with gapless excitations. As a result, the conductance rises from $G=e^2/h$ at temperatures below the critical temperature when nuclear spins are fully polarized to $G=2e^2/h$ at higher temperatures when the order is destroyed, featuring a relatively wide plateau in the intermediate regime. The theoretical results are compared with the experimental data for GaAs quantum wires obtained recently by Scheller et al. [Phys. Rev. Lett. 112, 066801 (2014)].