Regensburg 2019 – wissenschaftliches Programm
MA 7.12: Vortrag
Montag, 1. April 2019, 18:15–18:30, H37
Entropic stabilization of magnetic skyrmions in ultrathin films — •Stephan von Malottki1, Pavel F. Bessarab2, Soumyajyoti Haldar1, Anna Delin3, and Stefan Heinze1 — 1Institute of Theoretical Physics and Astrophysics, University of Kiel — 2School of Engineering and Natural Sciences - Science Institute, University of Iceland — 3Department of Applied Physics, School of Engineering Sciences, KTH, Kista
We show that thermal stability of magnetic skyrmions can be strongly affected by entropic effects . The lifetimes of isolated skyrmions in atomic Pd/Fe bilayers on Ir(111) and on Rh(111) are calculated in the framework of harmonic transition state theory based on an atomistic spin model parametrized from density functional theory. Depending on the system the attempt frequency for skyrmion collapse can change by up to nine orders of magnitude with the strength of the applied magnetic field. We demonstrate that this effect is due to a drastic change of entropy with skyrmion radius which opens a novel route towards stabilizing sub-10 nm skyrmions at room temperature.
von Malottki et al., arXiv:1811.12067