Embedded skyrmion bags in thin films of chiral magnets

Luyan Yang; Andrii S. Savchenko; Fengshan Zheng; Nikolai S. Kiselev; Filipp N. Rybakov; Xiaodong Han; Stefan Blügel; Rafal E. Dunin-Borkowski

doi:10.1002/adma.202403274

arXiv · 2403.16931

Embedded skyrmion bags in thin films of chiral magnets

Luyan Yang·Andrii S. Savchenko·Fengshan Zheng·Nikolai S. Kiselev·Filipp N. Rybakov·Xiaodong Han·Stefan Blügel·Rafal E. Dunin-Borkowski

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Abstract

Magnetic skyrmions are topologically nontrivial spin configurations that possess particle-like properties. Earlier research was mainly focused on a specific type of skyrmion with topological charge Q = -1. However, theoretical analyses of two-dimensional chiral magnets have predicted the existence of skyrmion bags -- solitons with arbitrary positive or negative topological charge. Although such spin textures are metastable states, recent experimental observations have confirmed the stability of isolated skyrmion bags in a limited range of applied magnetic fields. Here, by utilizing Lorentz transmission electron microscopy, we show the extraordinary stability of skyrmion bags in thin plates of B20-type FeGe. In particular, we show that skyrmion bags embedded within a skyrmion lattice remain stable even in zero or inverted external magnetic fields. A robust protocol for nucleating such embedded skyrmion bags is provided. Our results agree perfectly with micromagnetic simulations and establish thin plates of cubic chiral magnets as a powerful platform for exploring a broad spectrum of topological magnetic solitons.

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Luyan Yang, Andrii S. Savchenko, Fengshan Zheng, Nikolai S. Kiselev, Filipp N. Rybakov, Xiaodong Han, Stefan Blügel, Rafal E. Dunin-Borkowski. 2024-03-25. Embedded skyrmion bags in thin films of chiral magnets. https://doi.org/10.1002/adma.202403274

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