Laser-induced spatiotemporal dynamics of magnetic films

TL;DR

This paper develops a theoretical model for laser-induced magnetization dynamics in magnetic films, considering both thermal and nonthermal effects, and highlights how magnetoelastic coupling influences spin wave and phonon interactions with angle-dependent behaviors.

Contribution

It introduces a comprehensive theory that accounts for both inverse Faraday effect and heating in laser-driven magnetic dynamics, emphasizing magnetoelastic coupling effects.

Findings

Magnetoelastic coupling enables efficient spin wave-phonon conversion.

Distinct angle dependences differentiate thermal and nonthermal actuation.

The theory predicts specific propagation behaviors for magnetization dynamics.

Abstract

We present a theory for the coherent magnetization dynamics induced by a focused ultrafast laser beam in magnetic films, taking into account nonthermal (inverse Faraday effect) and thermal (heating) actuation. The dynamic conversion between spin waves and phonons is induced by the magnetoelastic coupling that allows efficient propagation of angular momentum. The anisotropy of the magnetoelastic coupling renders characteristic angle dependences of the magnetization propa-gation that are strikingly different for thermal and nonthermal actuation.