Optimizing skyrmion properties for technological applications: an atomistic perspective

Chiral magnetic skyrmions are not only of great scientific interest but also of potential relevance in information technology, data storage, and neuromorphic computing. Their desirable properties – such as their lifetime, mobility, and robustness with respect to external influences – depend hereby on the specific technological application. Therefore, the skyrmion properties need to be tuned accordingly to be able to compete with existing technologies or to even outperform those.

In this talk, I will present our recent works related to the optimization of skyrmion hosting materials and provide an atomistic insight into how skyrmion properties can be tuned. Our investigations are based on micromagnetic arguments as well as atomistic spin-dynamics simulations, carried out with our Spirit code [1]. To obtain static properties, we perform LLG and GNEB simulations, which provide us the energy barrier and the corresponding saddle point structure, and combine those with HTST [2] calculations to determine the lifetime prefactor. Additionally, we perform LLG simulations to investigate the dynamics of skyrmions.

In a recent publication [3], we showed that going beyond the micromagnetic limit, i.e., introducing frustration of magnetic interactions as well as considering structural aspects, provides a bright outlook for lifetime dependence on the materials properties. Additionally, I will show that the skyrmion profile, i.e., the functional dependence of the magnetization on the position relative to the skyrmion core, has a tremendous influence on skyrmion lifetime, stability, and dynamics, and I will demonstrate how the skyrmion profile can be tuned to optimize skyrmion properties.

[1] Spirit spin simulation framework, spirit-code.github.io

[2] P. F. Bessarab et al., Phys. Rev. B 85, 184409 (2012)

[3] M. Hoffmann et al., Phys. Rev. Lett. 124, 247201 (2020)