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arXiv · 1902.09708

Oriented Three-Dimensional Magnetic Biskyrmion in MnNiGa Bulk Crystals

Xiyang Li·Shilei Zhang·Hang Li·Diego Alba Venero·Jonathan S White·Robert Cubitt·Qingzhen Huang·Jie Chen·Lunhua He·Gerrit van der Laan·Wenhong Wang·Thorsten Hesjedal·Fangwei Wang
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Abstract

A biskyrmion consists of two bound, topologically stable skyrmion spin textures. These coffee-bean-shaped objects have been observed in real-space in thin plates using Lorentz transmission electron microscopy (LTEM). From LTEM imaging alone, it is not clear whether biskyrmions are surface-confined objects, or, analogously to skyrmions in non-centrosymmetric helimagnets, three-dimensional tube-like structures in bulk sample. Here, we investigate the biskyrmion form factor in single- and polycrystalline MnNiGa samples using small angle neutron scattering (SANS). We find that biskyrmions are not long-range ordered, not even in single-crystals. Surprisingly all of the disordered biskyrmions have their in-plane symmetry axis aligned along certain directions, governed by the magnetocrystalline anisotropy. This anisotropic nature of biskyrmions may be further exploited to encode information.

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Xiyang Li, Shilei Zhang, Hang Li, Diego Alba Venero, Jonathan S White, Robert Cubitt, Qingzhen Huang, Jie Chen, Lunhua He, Gerrit van der Laan, Wenhong Wang, Thorsten Hesjedal, Fangwei Wang. 2019-02-26. Oriented Three-Dimensional Magnetic Biskyrmion in MnNiGa Bulk Crystals. https://doi.org/10.1002/adma.201900264

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