Spontaneous creation and annihilation dynamics of magnetic skyrmions at elevated temperature

Session Information

Location: amf. P7 | "Gheorghe Asachi" Technical University of Iași (TUIAȘI)
Day: 2. Tuesday 16
Time: 08:50-09:00
Chairperson: N/A

Presentation Details

Presentation Type: Poster presentation
Title: Spontaneous creation and annihilation dynamics of magnetic skyrmions at elevated temperature
Abstract: Magnetic skyrmions are topological spin textures whose stability and dynamics are strongly affected by thermal fluctuations, particularly in ultrathin chiral magnetic systems where competing interactions act on the atomic scale.
A key challenge for their practical use is understanding how thermal fluctuations influence their nucleation, motion, stability, and annihilation. This is essential both for fundamental studies of topological matter and for assessing their robustness in realistic conditions. In this work [1], we investigate the spontaneous creation and annihilation dynamics of magnetic skyrmions in an Ir/Co/Pt ultrathin-film model using atomistic spin simulations parameterised from ab initio calculations, considering temperatures from 300 K to 500 K, with the 0 K configuration used as a reference state. Atomistic spin dynamics simulations are performed using VAMPIRE, enabling the investigation of complex topological spin structures at finite temperature.
Our analysis focuses on the stochastic finite-temperature regime, investigated using VAMPIRE atomistic spin dynamics simulations [2], in which the system evolves under the combined influence of exchange, magnetic anisotropy, Dzyaloshinskii-Moriya interaction, Zeeman coupling, and thermal noise. We show that, under an applied perpendicular magnetic field, increasing temperature can drive the system away from a uniformly magnetised state toward a regime in which skyrmions spontaneously appear as thermally activated topological excitations. Once formed, these textures exhibit fluctuating particle-like dynamics and finite lifetimes, eventually disappearing through thermally activated annihilation. At the same time, thermal fluctuations can also give rise to new nucleation events, leading to a dynamic balance between creation and annihilation processes.

[1] Wang, J., Strungaru, M., Ruta, S., Meo, A., Zhou, Y., Deák, A., ... & Chantrell, R. W. (2021). Spontaneous creation and annihilation dynamics of magnetic skyrmions at elevated temperature. Physical Review B, 104(5), 054420.
[2] Evans, R. F., Fan, W. J., Chureemart, P., Ostler, T. A., Ellis, M. O., & Chantrell, R. W. (2014). Atomistic spin model simulations of magnetic nanomaterials. Journal of Physics: Condensed Matter, 26(10), 103202.

Presenter

Dr Sergiu Ruta
Sheffield Hallam University | United Kingdom

Authors

1. Ruta, Sergiu | College of Business, Technology and Engineering, Sheffield Hallam University, UK
2. Wang, Junlin | School of Integrated Circuits, Guangdong University of Technology, Guangzhou, Guangdong, China
3. Strungaru, Mara | Department of Computer Science, The University of Manchester, Manchester M13 9PL, United Kingdom
4. Chubykalo-Fesenko, Oksana | Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain
5. Szunyogh, László | Department of Theoretical Physics, Budapest University of Technology and Economics, Budapest 1111, Hungary
6. Evans, Richard F. L. | Department of Physics, University of York, York YO10 5DD, United Kingdom
7. Chantrell, Roy | Department of Physics, University of York, York YO10 5DD, United Kingdom