Skyrmion morphology in ultrathin magnetic films

TL;DR

This study uses nitrogen-vacancy magnetic microscopy and simulations to analyze how disorder and magnetic history influence skyrmion morphology in ultrathin magnetic films, advancing understanding of their stability and dynamics.

Contribution

It demonstrates the impact of local pinning and disorder on skyrmion shape and size, supported by experimental imaging and micromagnetic simulations.

Findings

Skyrmion size and shape are affected by local pinning effects.

Disorder and magnetic history are key to skyrmion stabilization.

Simulations accurately reproduce experimental observations.

Abstract

Nitrogen-vacancy magnetic microscopy is employed in quenching mode as a non-invasive, high resolution tool to investigate the morphology of isolated skyrmions in ultrathin magnetic films. The skyrmion size and shape are found to be strongly affected by local pinning effects and magnetic field history. Micromagnetic simulations including static disorder, based on a physical model of grain-to-grain thickness variations, reproduce all experimental observations and reveal the key role of disorder and magnetic history in the stabilization of skyrmions in ultrathin magnetic films. This work opens the way to an in-depth understanding of skyrmion dynamics in real, disordered media.