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arXiv · 2503.18632

Nanometric skyrmion lattice from anisotropic exchange interactions in a centrosymmetric host

Max Hirschberger·Satoru Hayami·Yoshinori Tokura
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Abstract

Skyrmion formation in centrosymmetric magnets without Dzyaloshinskii-Moriya interactions was originally predicted from unbiased numerical techniques. However, no attempt has yet been made, by comparison to a real material, to determine the salient interaction terms and model parameters driving spin-vortex formation. We identify a Hamiltonian with anisotropic exchange couplings, local ion anisotropy, and four-spin interactions, which is generally applicable to this class of compounds. In the representative system Gd3Ru4Al12, anisotropic exchange drives a fragile balance between helical, skyrmion lattice, and transverse conical (cycloidal) orders. The model is severely constrained by the experimentally observed collapse of the SkL with a small in-plane magnetic field. For the zero-field helical state, we further anticipate that spins can be easily rotated out of the spiral plane by a tilted magnetic field or applied current.

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Max Hirschberger, Satoru Hayami, Yoshinori Tokura. 2025-03-24. Nanometric skyrmion lattice from anisotropic exchange interactions in a centrosymmetric host. https://doi.org/10.1088/1367-2630%2Fabdef9

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