Dynamic transport in a quantum wire driven by spin-orbit interaction

TL;DR

This paper explores how a non-stationary spin-orbit interaction, induced by a scanning probe, can generate and control charge and spin excitations in a gated 1D quantum wire, revealing tunable transport properties.

Contribution

It demonstrates that a contactless, dynamic spin-orbit interaction can induce charge currents and modify excitation velocities in a quantum wire, offering a new way to control 1D electron transport.

Findings

Charge current appears due to iSOI in the presence of Rashba SOI.

Spin-charge separation is broken by the iSOI.

Excitation velocities are strongly renormalized and tunable by gate potential.

Abstract

We consider a gated one-dimensional (1D) quantum wire disturbed in a contactless manner by an alternating electric field produced by a tip of a scanning probe microscope. In this schematic 1D electrons are driven not by a pulling electric field but rather by a non-stationary spin-orbit interaction (SOI) created by the tip. We show that a charge current appears in the wire in the presence of the Rashba SOI produced by the gate net charge and image charges of 1D electrons induced on the gate (iSOI). The iSOI contributes to the charge susceptibility by breaking the spin-charge separation between the charge- and spin collective excitations, generated by the probe. The velocity of the excitations is strongly renormalized by SOI, which opens a way to fine-tune the charge and spin response of 1D electrons by changing the gate potential. One of the modes softens upon increasing the gate potential to enhance the current response as well as the power dissipated in the system.