Coherent elastic excitation of spin waves

TL;DR

This paper models how elastic waves can excite spin waves in a ferromagnetic film, revealing interface states and predicting efficient sound-induced spin current generation for spintronic applications.

Contribution

It introduces a detailed model of elastic wave injection into ferromagnetic films, analyzing interface states and spin current pumping mechanisms.

Findings

Evanescent interface states arise when magnetization is normal to wave propagation.

Efficient acoustically induced spin current pumping is predicted.

Comparison of magnetization orientations reveals different interface phenomena.

Abstract

We model the injection of elastic waves into a ferromagnetic film (F) by a non-magnetic transducer (N). We compare the configurations in which the magnetization is normal and parallel to the wave propagation. The lack of axial symmetry in the former results in the emergence of evanescent interface states. We compute the energy-flux transmission across the N$|$F interface and sound-induced magnetization dynamics in the ferromagnet. We predict efficient acoustically induced pumping of spin current into a metal contact attached to F.