Observation of a One-Dimensional Spin-Orbit Gap in a Quantum Wire

TL;DR

This paper reports the first experimental observation of a spin-orbit gap in a one-dimensional quantum wire, demonstrating clear conductance signals associated with spin currents induced by spin-orbit interaction.

Contribution

It provides the first direct evidence of a spin-orbit gap in a 1D system, advancing understanding of spin transport in low-dimensional structures.

Findings

Observation of a spin-orbit gap in a quantum wire

Detection of spin currents via conductance measurements

Advancement in spintronics understanding

Abstract

Understanding the flow of spins in magnetic layered structures has enabled an increase in data storage density in hard drives over the past decade of more than two orders of magnitude1. Following this remarkable success, the field of 'spintronics' or spin-based electronics is moving beyond effects based on local spin polarisation and is turning its attention to spin-orbit interaction (SOI) effects, which hold promise for the production, detection and manipulation of spin currents, allowing coherent transmission of information within a device. While SOI-induced spin transport effects have been observed in two- and three-dimensional samples, these have been subtle and elusive, often detected only indirectly in electrical transport or else with more sophisticated techniques. Here we present the first observation of a predicted 'spin-orbit gap' in a one-dimensional sample, where counter-propagating spins, constituting a spin current, are accompanied by a clear signal in the easily-measured linear conductance of the system.