Blueprint for deterministic all-optical switching of magnetization

TL;DR

This paper provides a comprehensive model and experimental validation for deterministic all-optical magnetization switching in ferrimagnets using short heat pulses, offering a blueprint for future magnetic data storage technologies.

Contribution

It introduces a realistic macrospin model and demonstrates pathways for magnetization reversal, resolving previous controversies and guiding the design of reliable all-optical switching in ferrimagnets.

Findings

Magnetization can be reversed via multiple pathways with heat pulses.

Experimental validation in GdFeCo alloys confirms the model.

Blueprint for achieving deterministic switching in various ferrimagnets.

Abstract

We resolve a significant controversy about how to understand and engineer single-shot all-optical switching of magnetization in ferrimagnets using femto- or picosecond-long heat pulses. By realistically modelling a generic ferrimagnet as two coupled macrospins, we comprehensively show that the net magnetization can be reversed via different pathways, using a heat pulse with duration spanning all relevant timescales within the non-adiabatic limit. This conceptual understanding is fully validated by experiments studying the material and optical limits at which the switching process in GdFeCo alloys loses its reliability. Our interpretation and results constitute a blueprint for understanding how deterministic all-optical switching can be achieved in alternative ferrimagnets using short thermal pulses.