Mechanical generation of spin current by spin-rotation coupling

TL;DR

This paper proposes a novel method to generate spin currents in nonmagnetic materials using spin-rotation coupling and surface acoustic waves, avoiding the need for magnetic moments or spin-orbit interactions.

Contribution

It introduces a new mechanism for spin current generation based on spin-rotation coupling and provides theoretical calculations for its effectiveness in nonmagnetic materials.

Findings

Larger spin currents are achievable in materials with longer spin lifetimes.

Surface acoustic waves can induce detectable spin accumulation.

The method does not require magnetic moments or spin-orbit coupling.

Abstract

Spin-rotation coupling, which is responsible for angular momentum conversion between the electron spin and rotational deformations of elastic media, is exploited for generating spin current. This method requires neither magnetic moments nor spin-orbit interaction. The spin current generated in nonmagnets is calculated in presence of surface acoustic waves. We solve the spin diffusion equation, extended to include spin-rotation coupling, and find that larger spin currents can be obtained in materials with longer spin lifetimes. Spin accumulation induced on the surface is predicted to be detectable by time-resolved Kerr spectroscopy.