Regensburg 2022 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 20: Focus Session: Revealing Multidimensional Spin Textures and their Dynamics via X-rays and Electrons
MA 20.7: Vortrag
Mittwoch, 7. September 2022, 12:45–13:00, H37
All-electron holography of hopfions enabled by magneto-induced charges — •Moritz Winterott1,2 and Samir Lounis1,2 — 1Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich & JARA, D-52425 Jülich, Germany — 2Faculty of Physics, University of Duisburg-Essen and CENIDE, 47053 Duisburg, Germany
In recent years, far-reaching progress has been made in the field of topological particles. In addition to the well-known skyrmions, three-dimensional topological particles such as hopfions, bobbers and cocoons, are also becoming increasingly interesting. Thereby, a major challenge is the visualisation and recognition of such topological particles hidden in bulk materials. An intuitiv approach is to resolve their magnetic contrast, which is highly non-trivial, especially for antiferromagnetic textures where the overall signals are expected to vanish. Here we demonstrate that the charge carried by such topological objects carries specific dependencies on the misalignement of the magnetic moments, which enable their identification without the need for spin-resolved measurements. We utilize multiple-scattering theory and address the case of ferro- and anti-ferromagnetic hopfions. We identify the achiral and chiral-induced charges. Spin-orbit interaction (SOI) gives rise to the latter in 1st order similarly to the Dzyaloshinskii-Moriya interact and to anisotropic terms, 2nd order in SOI. We proceed to a systematic electron holography of the distinct magneto-induced charges, which provide a direct link to experiments.