SKM 2021 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 5: Posters Magnetism II
MA 5.14: Poster
Dienstag, 28. September 2021, 10:00–13:00, P
Mode following method for magnetic systems — •Stephan von Malottki1,2, Moritz A. Goerzen2, Hendrik Schrautzer1,2, Pavel F. Bessarab1, and Stefan Heinze2 — 1Science Institute, University of Iceland, Reykjavík — 2ITAP, University of Kiel, Germany
The average lifetime of metastable magnetic states is commonly determined by harmonic transition state theory (HTST) [1] or the related Langer’s theory [2], resulting in an Arrhenius-law depending on the thermal energy, the energy barrier and the pre-exponential factor. The latter contains information about the dynamics and entropic effects of the transition and is often challenging to obtain. In the past, the application of HTST calculations to magnetic skyrmions has been limited to cases in which the harmonic and zero-mode approximations are justified [1-3]. Other cases, such as the collapse of magnetic skyrmions via the chimera transition [2-4] or the collapse of antiskyrmions [4] were not always accessible. Here, we present a numerical method to evaluate the entropic contribution of individual Eigenmodes beyond the harmonic approximation. With this method, not only the quality of the harmonic and zero-mode approximations can be evaluated, but also the direct numerical calculation of the entropic contributions becomes feasible, which allows access to intermediate temperature regimes that could not be treated with conventional HTST.
[1] P. Bessarab et al. Sci. Rep. 8, 3433 (2018)
[2] L. Desplat et al. PRB 99, 174409 (2019)
[3] F. Muckel et al. Nat. Phys. 17, 395-402 (2021)
[4] S. Meyer et al. Nat. Commun. 10 3823, (2019)