Purely electric spin pumping in one-dimension

TL;DR

This paper demonstrates theoretically that a one-dimensional metallic wire can exhibit quantum spin pumping driven solely by electric fields, without charge transfer, through non-commuting local spin-orbit interactions.

Contribution

It introduces a novel mechanism for spin pumping in 1D systems using time-varying electric fields that generate non-commuting Rashba spin-orbit couplings.

Findings

Spin pumping can occur without charge transfer in 1D systems.

Electric fields can induce non-commuting Rashba interactions leading to spin transport.

The effect respects time-reversal symmetry and is a unique quantum phenomenon.

Abstract

We show theoretically that a simple one dimensional system (such as metallic wire) can display quantum spin pumping possibly without pushing any charge. It is achieved by applying two slowly varying orthogonal gate electric fields on different sections of the wire, thereby generating local spin-orbit (Rashba) terms such that unitary transformations at different places do not commute. This construction is a unique manifestation of a spin-orbit observable effect in purely one dimensional systems with potentials respecting time-reversal symmetry.