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Large anisotropic deformation of skyrmions in strained crystal

Abstract

Mechanical control of magnetism is an important and promising approach in spintronics. To date, strain control has mostly been demonstrated in ferromagnetic structures by exploiting a change in magnetocrystalline anisotropy. It would be desirable to achieve large strain effects on magnetic nanostructures. Here, using in situ Lorentz transmission electron microscopy, we demonstrate that anisotropic strain as small as 0.3% in a chiral magnet of FeGe induces very large deformations in magnetic skyrmions1,2, as well as distortions of the skyrmion crystal lattice on the order of 20%. Skyrmions are stabilized by the Dzyaloshinskii–Moriya interaction3,4, originating from a chiral crystal structure. Our results show that the change in the modulation of the strength of this interaction is amplified by two orders of magnitude with respect to changes in the crystal lattice due to an applied strain. Our findings may provide a mechanism to achieve strain control of topological magnetic structures based on the Dzyaloshinskii–Moriya interaction.

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Figure 1: Device structure and observed Lorentz TEM images of the SkX.
Figure 2: Evaluation of SkX deformation in reciprocal space.
Figure 3: Evaluation of individual skyrmion deformation.

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Acknowledgements

The authors thank Y. Okamura, N. Shibata, Y. Ikuhara, T. Matsuda, A. Kikkawa, Y. Nii, D. Morikawa and X.Z. Yu for discussions. This study was supported by a Grant-in-Aid for Scientific Research (grant no. 24224009) from MEXT and by the Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST Program). K.S. was supported by the Japan Society for the Promotion of Science (JSPS) through a Grant-in-Aid for JSPS Fellows (no. 2609358) and the Program for Leading Graduate Schools (MERIT). J.I. was supported by a Grant-in-Aid for JSPS Fellows (no. 2610547).

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Correspondence to K. Shibata or Y. Tokura.

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Shibata, K., Iwasaki, J., Kanazawa, N. et al. Large anisotropic deformation of skyrmions in strained crystal. Nature Nanotech 10, 589–592 (2015). https://doi.org/10.1038/nnano.2015.113

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