Curved One-Dimensional Wire as a Spin Rotator

TL;DR

This paper introduces a novel semiconductor device using a curved one-dimensional wire with spin-orbit interaction to efficiently rotate electron spins without magnetic contacts or external radiation, acting as a reflectionless spin switcher.

Contribution

It presents a new design for a spin rotator based on curved ballistic wires with Rashba spin-orbit coupling, enabling high-speed, reflectionless spin manipulation.

Findings

Device can redistribute current densities between spin modes without backscattering.

Spin polarization can be controlled by Rashba constant, magnetic field, and curvature radius.

Proposed structure functions effectively with parameters relevant for InAs.

Abstract

We propose a semiconductor structure that can rotate the electron spin without using ferromagnetic contacts, tunneling barriers, external radiation etc. The structure consists of a strongly curved one-dimensional ballistic wire with intrinsic spin-orbit interactions of Rashba type. Our calculations and analytical formulae show that the proposed device can redistribute the current densities between the two spin-split modes without backscattering and, thus, serve as a reflectionless and high-speed spin switcher. Using parameters relevant for InAs we investigate the projection of current density spin polarization on the spin-quantization axis as a function of the Rashba constant, external magnetic field, and radius of the wire's curvature.