Spin transport in mesoscopic rings with inhomogeneous spin-orbit coupling

TL;DR

This paper investigates how inhomogeneous spin-orbit interactions in mesoscopic rings influence electron spin transport, revealing that spatial variations enhance quantum interference effects and enable control of spin currents with magnetic fields.

Contribution

It demonstrates that inhomogeneous spin-orbit coupling significantly amplifies spin-dependent quantum interference in mesoscopic rings, providing new insights into spin control mechanisms.

Findings

Inhomogeneous SO interactions strengthen spin-dependent quantum interference.

Spin currents can be manipulated with small external magnetic fields.

Mesoscopic spin Hall effects are explained via fictitious magnetic flux.

Abstract

We revisit the problem of electron transport through mesoscopic rings with spin-orbit (SO) interaction. In the well-known path-integral approach, the scattering states for a quasi-1D ring with quasi-1D leads can be expressed in terms of spinless electrons subject to a fictitious magnetic flux. We show that spin-dependent quantum-interference effects in small rings are strongest for spatially inhomogeneous SO interactions, in which case spin currents can be controlled by a small external magnetic field. Mesoscopic spin Hall effects in four-terminal rings can also be understood in terms of the fictitious magnetic flux.