# Magnetic skyrmions in confined geometries : effect of the magnetic field and the disorder

## TL;DR

This study investigates how lateral confinement, magnetic fields, and disorder influence the size and stability of magnetic skyrmions in nanostructures, demonstrating tunability and pinning effects at room temperature.

## Contribution

It provides new insights into controlling skyrmion size and stability through nanostructure geometry, magnetic fields, and disorder, supported by experimental and micromagnetic simulation data.

## Key findings

- Skyrmion size can be tuned by nanostructure dimensions and magnetic field.
- Pinning significantly affects skyrmion stability and size.
- Micromagnetic simulations match experimental observations.

## Abstract

We report on the effect of the lateral confinement and a perpendicular magnetic field on isolated room-temperature magnetic skyrmions in sputtered Pt/Co/MgO nanotracks and nanodots. We show that the skyrmions size can be easily tuned by playing on the lateral dimensions of the nanostructures and by using external magnetic field amplitudes of a few mT, which allow to reach sub-100 nm diameters. Our XMCD-PEEM observations also highlight the important role of the pinning on the skyrmions size and stability under an out-of-plane magnetic field. Micromagnetic simulations reveal that the effect of local pinning can be well accounted for by considering the thin film grain structure with local anisotropy variations and reproduce well the dependence of the skyrmion diameter on the magnetic field and the geometry.