Direct observation of non-equilibrium spin population in quasi-one-dimensional nanostructures

TL;DR

This paper reports the direct observation of non-equilibrium spin populations in quasi-one-dimensional nanostructures, revealing how spin polarization can be electrically manipulated in semiconductor nanowires.

Contribution

It introduces a new electrical method to observe and control spin populations in quantum wires under non-equilibrium conditions.

Findings

First subband filled predominantly by one spin species

Spin polarization varies with magnetic field and bias

Electrical control of spin-polarized currents demonstrated

Abstract

Observation of the interplay between interacting energy levels of two spin species is limited by the difficulties in continuously tracking energy levels, and thus leaves spin transport in quantum wires still not well understood. We present a dc conductance feature in the non-equilibrium transport regime, a direct indication that the first one-dimensional subband is filled mostly by one spin species only. How this anomalous spin population changes with magnetic field and source-drain bias is directly measured. We show the source-drain bias changes spin polarisation in semiconductor nanowires, providing a fully electrical method for the creation and manipulation of spin polarization as well as spin-polarized currents.