Magnetically-controlled impurities in quantum wires with strong Rashba coupling

TL;DR

This paper studies how strong spin-orbit interaction and magnetic fields influence electron transport in quantum wires with impurities, revealing a mechanism for negative magnetoresistance due to suppressed potential scattering.

Contribution

It introduces a novel analysis of impurity scattering modulation via Rashba coupling and magnetic fields in one-dimensional systems with strong spin-orbit interaction.

Findings

Magnetic field induces momentum-dependent spin polarization.

Spin-flip scattering appears at first order in magnetic field.

Potential scattering can be suppressed by tuning Fermi level and Rashba coupling.

Abstract

We investigate the effect of strong spin-orbit interaction on the electronic transport through non-magnetic impurities in one-dimensional systems. When a perpendicular magnetic field is applied, the electron spin polarization becomes momentum-dependent and spin-flip scattering appears, to first order in the applied field, in addition to the usual potential scattering. We analyze a situation in which, by tuning the Fermi level and the Rashba coupling, the magnetic field can suppress the potential scattering. This mechanism should give rise to a significant negative magnetoresistance in the limit of large barriers.