Skyrmion stacking in stray field-coupled ultrathin ferromagnetic multilayers

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Hauptverfasser: Dubicki, N. J., Slastikov, V. V., Bernand-Mantel, A., Muratov, C. B.
Format: Preprint
Veröffentlicht: 2025
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author Dubicki, N. J.
Slastikov, V. V.
Bernand-Mantel, A.
Muratov, C. B.
author_facet Dubicki, N. J.
Slastikov, V. V.
Bernand-Mantel, A.
Muratov, C. B.
contents This paper explores the energy landscape of ferromagnetic multilayer heterostructures that feature magnetic skyrmions -- tiny whirls of spins with non-trivial topology -- in each magnetic layer. Such magnetic heterostructures have been recently pursued as possible hosts of room temperature stable magnetic skyrmions suitable for the next generation of low power information technologies and unconventional computing. The presence of stacked skyrmions in the adjacent layers gives rise to a strongly coupled nonlinear system, whereby the induced magnetic field plays a crucial stabilizing role. Starting with the micromagnetic modeling framework, we derive a general reduced energy functional for a fixed number of ultrathin ferromagnetic layers with perpendicular magnetocrystalline anisotropy. We next investigate this energy functional in the regime in which the energy is dominated by the intralayer exchange interaction and formally obtain a finite-dimensional description governed by the energy of a system of one skyrmion per layer as a function of the position, radius and the rotation angle of each of theses skyrmions. For the latter, we prove that energy minimizers exist for all fixed skyrmion locations. We then focus on the simplest case of stray field-coupled ferromagnetic bilayers and completely characterize the energy minimizers. We show that the global energy minimizers exist and consist of two stray field-stabilized Néel skyrmions with antiparallel in-plane magnetization components. We also calculate the energy of two skyrmions of equal radius as a function of their separation distance.
format Preprint
id arxiv_https___arxiv_org_abs_2505_14649
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Skyrmion stacking in stray field-coupled ultrathin ferromagnetic multilayers
Dubicki, N. J.
Slastikov, V. V.
Bernand-Mantel, A.
Muratov, C. B.
Analysis of PDEs
Mesoscale and Nanoscale Physics
Mathematical Physics
Pattern Formation and Solitons
This paper explores the energy landscape of ferromagnetic multilayer heterostructures that feature magnetic skyrmions -- tiny whirls of spins with non-trivial topology -- in each magnetic layer. Such magnetic heterostructures have been recently pursued as possible hosts of room temperature stable magnetic skyrmions suitable for the next generation of low power information technologies and unconventional computing. The presence of stacked skyrmions in the adjacent layers gives rise to a strongly coupled nonlinear system, whereby the induced magnetic field plays a crucial stabilizing role. Starting with the micromagnetic modeling framework, we derive a general reduced energy functional for a fixed number of ultrathin ferromagnetic layers with perpendicular magnetocrystalline anisotropy. We next investigate this energy functional in the regime in which the energy is dominated by the intralayer exchange interaction and formally obtain a finite-dimensional description governed by the energy of a system of one skyrmion per layer as a function of the position, radius and the rotation angle of each of theses skyrmions. For the latter, we prove that energy minimizers exist for all fixed skyrmion locations. We then focus on the simplest case of stray field-coupled ferromagnetic bilayers and completely characterize the energy minimizers. We show that the global energy minimizers exist and consist of two stray field-stabilized Néel skyrmions with antiparallel in-plane magnetization components. We also calculate the energy of two skyrmions of equal radius as a function of their separation distance.
title Skyrmion stacking in stray field-coupled ultrathin ferromagnetic multilayers
topic Analysis of PDEs
Mesoscale and Nanoscale Physics
Mathematical Physics
Pattern Formation and Solitons
url https://arxiv.org/abs/2505.14649