0.7-anomaly and magnetotransport of disordered quantum wires

TL;DR

This paper investigates the 0.7 conductance plateau in disordered quantum wires, revealing how disorder and magnetic fields influence conductance and enabling a new method to measure the effective g-factor.

Contribution

It demonstrates the coexistence of transmission resonances with the 0.7 plateau and introduces a method to determine the g-factor in disordered quantum wires.

Findings

Resonances coexist with the 0.7 conductance plateau.

Magnetic field and electron density affect transmission resonances.

Method for measuring the effective g-factor in disordered wires.

Abstract

The unexpected "0.7" plateau of conductance quantisation is usually observed for ballistic one-dimensional devices. In this work we study a quasi-ballistic quantum wire, for which the disorder induced backscattering reduces the conductance quantisation steps. We find that the transmission probability resonances coexist with the anomalous plateau. The studies of these resonances as a function of the in-plane magnetic field and electron density point to the presence of spin polarisation at low carrier concentrations and constitute a method for the determination of the effective g-factor suitable for disordered quantum wires.