Berlin 2024 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 12: Skyrmions I
MA 12.6: Vortrag
Montag, 18. März 2024, 16:15–16:30, EB 301
The mechanism and timescale of skyrmion localization during all-optical topological switching — •Daniel Metternich1,2, Michael Schneider3, Torstein Hegstad4, Giuseppe Mercurio5, Riccardo Battistelli1,2, Christopher Klose3, Victor Deinhardt1,2, Krishnanjana Puzhekadavil Joy2, Manas Patra1,2, Steffen Wittrock1, Marcel Möller6, Sergey Zayko6, Claus Ropers6, Johan Mentink4, Bastian Pfau3, and Felix Büttner1,2 — 1Helmholtz-Zentrum Berlin, Germany — 2Universität Augsburg, Germany — 3Max-Born-Institut, Germany — 4Radboud Universiteit, Netherlands — 5EuXFEL, Hamburg, Germany — 6Max-Planck-Institut, Göttingen, Germany
Heating a Co/Pt-multilayer with an optical laser pulse can create skyrmions at picosecond timescales. While the nucleation of these features is understood as being facilitated by transient fluctuations, the mechanisms of localization during this process has remained a puzzle.
Here, we present a real-time study of the skyrmion localization dynamics, conducted via time resolved SAXS at the EuXFEL. Using a periodic grid of ion irradiated areas (where the magnetic anisotropy is reduced), we can distinguish in the Fourier-space scattering signal between the time evolution at localization centers and evolution of homogeneous fluctuations. We observe that the localization process sets in only after a phase of homogeneous, fluctuation-driven nucleation events. Atomistic simulations and analytical modeling show that the localization is driven by a larger annihilation energy barrier and hence a lower skyrmion decay rate in the ion-irradiated areas.
Keywords: optical skyrmion nucleation; time resolved SAXS; atomistic simulations; Co/Pt multilayer