Spin-dependent transport in a quasiballistic quantum wire

TL;DR

This paper investigates spin-dependent transport in a 5 μm long quantum wire, revealing spin-splitting, deviations from conductance quantization, and the effects of disorder and electron interactions on conductance behavior.

Contribution

It provides experimental evidence of spin-dependent conductance deviations and the influence of disorder and interactions in a quasiballistic 1D quantum wire.

Findings

Spin-splitting of conductance steps in magnetic field

Deviation from quantization is small for parallel spins

Plateau near 0.3 e^2/h increases with temperature

Abstract

We describe the transport properties of a 5 $\mu$m long one-dimensional (1D) quantum wire. Reduction of conductance plateaux due to the introduction of weakly disorder scattering are observed. In an in-plane magnetic field, we observe spin-splitting of the reduced conductance steps. Our experimental results provide evidence that deviation from conductance quantisation is very small for electrons with spin parallel and is about 1/3 for electrons with spin anti-parallel. Moreover, in a high in-plane magnetic field, a spin-polarised 1D channel shows a plateau-like structure close to $0.3 \times e^2/h$ which strengthens with {\em increasing} temperatures. It is suggested that these results arise from the combination of disorder and the electron-electron interactions in the 1D electron gas.