Manipulating Magnetization of a Nanomagnet by Surface Acoustic Waves: Spin-Rotation Mechanism

TL;DR

This paper demonstrates a universal method to switch the magnetization of a nanoparticle using surface acoustic waves, relying on shear deformation-induced effective magnetic fields, with potential applications in magnetic data storage.

Contribution

It introduces a novel spin-rotation mechanism for magnetization control via surface acoustic waves, independent of particle or substrate structure.

Findings

Magnetization can be reversed by shear deformation from surface acoustic waves.

Analytical and numerical models confirm the effectiveness of the mechanism.

The process is controllable through the frequency of surface phonons.

Abstract

We show that the magnetic moment of a nanoparticle embedded in the surface of a solid can be switched by surface acoustic waves (SAW) in the GHz frequency range via a universal mechanism that does not depend on the structure of the particle and the structure of the substrate. It is based upon generation of the effective ac magnetic field in the coordinate frame of the nanoparticle by the shear deformation of the surface due to SAW. The magnetization reversal occurs via a consecutive absorption of surface phonons of the controlled variable frequency. We derive analytical equations governing this process and solve them numerically for the practical range of parameters.