Magnetization dynamics and reversal of two-dimensional magnets

TL;DR

This paper develops a micromagnetic theory tailored for 2D magnets, capturing their unique rapid demagnetization and remagnetization dynamics during reversal, which differ fundamentally from 3D magnets.

Contribution

It introduces a new micromagnetic framework explicitly modeling the fast dynamics of 2D magnets during reversal, addressing limitations of classical models.

Findings

Reversal dynamics are faster in 2D magnets due to intrinsic spin fluctuations.

Magnetization trajectories in 2D magnets differ significantly from 3D cases.

The theory highlights the collapse and recovery processes unique to 2D magnetic systems.

Abstract

Micromagnetics simulation based on the classical Landau-Lifshitz-Gilbert (LLG) equation has long been a powerful method for modeling magnetization dynamics and reversal of three-dimensional (3D) magnets. For two-dimensional (2D) magnets, the magnetization reversal always accompanies the collapse of the magnetization even at low temperatures due to intrinsic strong spin fluctuation. We propose a micromagnetic theory that explicitly takes into account the rapid demagnetization and remagnetization dynamics of 2D magnets during magnetization reversal. We apply the theory to a single-domain magnet to illustrate fundamental differences in magnetization trajectories and reversal times for 2D and 3D magnets.