Imprinting spatial helicity structure of vector vortex beam on spin texture in semiconductors

TL;DR

This paper demonstrates how the spatial polarization structure of vector vortex beams can be transferred to and control the spin textures in semiconductor quantum wells, enabling the generation of tunable helical spin waves.

Contribution

It introduces a novel method to imprint and manipulate complex spin textures in semiconductors using structured light with topological polarization features.

Findings

Successful transfer of polarization structure to spin textures

Generation of controllable helical spin waves

Single beam creates opposite phase spin waves

Abstract

We present the transfer of the spatially variant polarization of topologically structured light to the spatial spin texture in a semiconductor quantum well. The electron spin texture, which is a circular pattern with repeating spin-up and spin-down states whose repetition rate is determined by the topological charge, is directly excited by a vector vortex beam with a spatial helicity structure. The generated spin texture efficiently evolves into a helical spin wave pattern owing to the spin-orbit effective magnetic fields in the persistent spin helix state by controlling the spatial wave number of the excited spin mode. By tuning the repetition length and azimuthal angle, we simultaneously generate helical spin waves with opposite phases by a single beam.