Collapse of Skyrmions in 2d Ferro- and Antiferromagnets

TL;DR

This study analyzes how the discrete nature of crystal lattices causes skyrmions to collapse in 2D ferro- and antiferromagnets, revealing different scaling laws for their lifetimes.

Contribution

It provides an analytical and numerical comparison of skyrmion collapse in ferro- and antiferromagnets, highlighting the different lifetime scaling behaviors.

Findings

Skyrmion lifetime scales as (lambda_0/a)^5 in ferromagnets.

Skyrmion lifetime scales as (lambda_0/a)^2.15 in antiferromagnets.

Antiferromagnetic skyrmions are shorter-lived than ferromagnetic ones.

Abstract

Collapse of a skyrmion due to the discreteness of a crystal lattice in isotropic two-dimensional ferro- and antiferromagnets has been studied analytically and by numerical solution of equations of motion for up to 2000 x 2000 classical spins on a square lattice coupled via Heisenberg exchange interaction. Excellent agreement between analytical and numerical results has been achieved. The lifetime of the skyrmion scales with its initial size, lambda_0, as(lambda_0/a)^5 in ferromagnets and as (lambda_0/a)^2.15 in antiferromagnets, with a being the lattice parameter. This makes antiferromagnetic skyrmions significantly shorter lived than ferromagnetic skyrmions.