Skyrmion in a real magnetic film

TL;DR

This paper investigates the stability and decay dynamics of skyrmions in real magnetic films, highlighting the role of lattice discreteness and uniaxial anisotropy in their behavior.

Contribution

It provides a detailed analysis of skyrmion decay mechanisms and demonstrates how uniaxial anisotropy stabilizes skyrmions in magnetic films.

Findings

Lattice discreteness causes slow magnetization rotation leading to skyrmion decay.

Uniaxial anisotropy stabilizes skyrmions against decay.

The radius evolution of decaying skyrmions is quantitatively modeled.

Abstract

Skyrmions are the magnetic defects in an ultrathin magnetic film, similar to the bubble domains in the thicker films. Even weak uniaxial anisotropy determines its radius unambiguously. We consider the dynamics of the skyrmion decay. We show that the discreteness of the lattice in an isotropic 2D magnet leads to a slow rotation of the local magnetization in the skyrmion and, provided a small dissipation, to decay of the skyrmion. The radius of such a skyrmion as a function of time is calculated. We prove that uniaxial anisotropy stabilizes the skyrmion and study the relaxation process.