Thermal stability and topological protection of skyrmions in nanotracks

TL;DR

This study investigates the thermal stability of magnetic skyrmions in nanotracks, revealing that boundary effects lower energy barriers and challenge their topological protection, impacting their suitability for data storage at room temperature.

Contribution

The paper identifies multiple transition pathways for skyrmion stability and demonstrates the lack of topological protection in finite-sized systems through energy barrier analysis.

Findings

Boundary-mediated transitions have lower energy barriers.

Skyrmions lack topological protection in finite systems.

Energy barriers are too small for room-temperature storage.

Abstract

Magnetic skyrmions are hailed as a potential technology for data storage and other data processing devices. However, their stability against thermal fluctuations is an open question that must be answered before skyrmion-based devices can be designed. In this work, we study paths in the energy landscape via which the transition between the skyrmion and the uniform state can occur in interfacial Dzyaloshinskii-Moriya finite-sized systems. We find three mechanisms the system can take in the process of skyrmion nucleation or destruction and identify that the transition facilitated by the boundary has a significantly lower energy barrier than the other energy paths. This clearly demonstrates the lack of the skyrmion topological protection in finite-sized magnetic systems. Overall, the energy barriers of the system under investigation are too small for storage applications at room temperature, but research into device materials, geometry and design may be able to address this.