Model for multi-shot all-thermal all-optical switching in ferromagnets

TL;DR

This paper introduces a heat-driven model for multi-shot all-optical magnetic switching in ferromagnets, emphasizing the role of Magnetic Circular Dichroism and predicting minimal MCD requirements for switching.

Contribution

The paper presents a new heat-based model for multi-shot AOS in ferromagnets, incorporating MCD effects, and reproduces experimental results through simulations.

Findings

AOS can occur with as little as 0.5% MCD after multiple laser shots.

The model predicts the minimum MCD needed for switching.

Simulations successfully reproduce previous experimental AOS results.

Abstract

All optical magnetic switching (AOS) is a recently observed rich and puzzling phenomenon that offers promis- ing technological applications. However, fundamental understanding of the underlying mechanisms remains elusive. Here we present a new model for multi-shot helicity-dependent AOS in ferromagnetic materials based on a purely heat-driven mechanism in the presence of Magnetic Circular Dichroism (MCD). We predict that AOS should be possible with as little as 0.5% of MCD, after a minimum number of laser shots. Finally, we re- produce previous AOS results by simulating the sweeping of a laser beam on an FePtC granular ferromagnetic film.