Origin of temperature and field dependence of magnetic skyrmion size in ultrathin nanodots

TL;DR

This paper presents a universal micromagnetic model to analyze how temperature and magnetic field influence the size and stability of skyrmions in ultrathin nanodots, aiding spintronic device development.

Contribution

It introduces a comprehensive model for skyrmion stability considering temperature and field effects in ultrathin ferromagnetic dots, highlighting size-dependent stability regimes.

Findings

Small skyrmions are metastable, large skyrmions are stable ground states.

Skyrmion size dependence on temperature and field varies with energy profile.

Results suggest pathways for designing materials for skyrmion-based devices.

Abstract

Understanding the physical properties of magnetic skyrmions is important for fundamental research with the aim to develop new spintronic device paradigms where both logic and memory can be integrated at the same level. Here, we show a universal model based on the micromagnetic formalism that can be used to study skyrmion stability as a function of magnetic field and temperature. We consider ultrathin, circular ferromagnetic magnetic dots. Our results show that magnetic skyrmions with a small radius compared to the dot radius are always metastable, while large radius skyrmions form a stable ground state. The change of energy profile determines the weak (strong) size dependence of the metastable (stable) skyrmion as a function of temperature and/or field. These results can open a path toward the design of optimal materials for skyrmion based devices.