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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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References

  1. Bogdanov, A. N. & Yablonskii, D. A. Thermodynamically stable ‘vortices’ in magnetically ordered crystals. The mixed state of magnets. Sov. Phys. JETP 68, 101–103 (1989).

    Google Scholar 

  2. Rössler, U. K., Bogdanov, A. N. & Pfleiderer, C. Spontaneous skyrmion ground states in magnetic metals. Nature 442, 797–801 (2006).

    Article  Google Scholar 

  3. Dzyaloshinsky, I. A thermodynamic theory of ‘weak’ ferromagnetism of antiferromagnetics. J. Phys. Chem. Solids 4, 241–255 (1958).

    Article  CAS  Google Scholar 

  4. Moriya, T. Anisotropic superexchange interaction and weak ferromagnetism. Phys. Rev. 120, 91–98 (1960).

    Article  CAS  Google Scholar 

  5. Mühlbauer, S. et al. Skyrmion lattice in a chiral magnet. Science 323, 915–919 (2009).

    Article  Google Scholar 

  6. Münzer, W. et al. Skyrmion lattice in the doped semiconductor Fe1−xCoxSi. Phys. Rev. B 81, 041203(R) (2010).

    Article  Google Scholar 

  7. Adams, T. et al. Long-wavelength helimagnetic order and skyrmion lattice phase in Cu2OSeO3 . Phys. Rev. Lett. 108, 237204 (2012).

    Article  CAS  Google Scholar 

  8. Moskvin, E. et al. Complex chiral modulations in FeGe close to magnetic ordering. Phys. Rev. Lett. 110, 077207 (2013).

    Article  CAS  Google Scholar 

  9. Yu, X. Z. et al. Real-space observation of a two-dimensional skyrmion crystal. Nature 465, 901–904 (2010).

    Article  CAS  Google Scholar 

  10. Yu, X. Z. et al. Near room-temperature formation of a skyrmion crystal in thin-films of the helimagnet FeGe. Nature Mater. 10, 106–109 (2011).

    Article  CAS  Google Scholar 

  11. Tonomura, A. et al. Real-space observation of skyrmion lattice in helimagnet MnSi thin samples. Nano Lett. 12, 1673–1677 (2012).

    Article  CAS  Google Scholar 

  12. Seki, S., Yu, X. Z., Ishiwata, S. & Tokura, Y. Observation of skyrmions in a multiferroic material. Science 336, 198–201 (2012).

    Article  CAS  Google Scholar 

  13. Shibata, K. et al. Towards control of the size and helicity of skyrmions in helimagnetic alloys by spin–orbit coupling. Nature Nanotech. 8, 723–728 (2013).

    Article  CAS  Google Scholar 

  14. Morikawa, D., Shibata, K., Kanazawa, N., Yu, X. Z. & Tokura, Y. Crystal chirality and skyrmion helicity in MnSi and (Fe, Co)Si as determined by transmission electron microscopy. Phys. Rev. B 88, 024408 (2013).

    Article  Google Scholar 

  15. Nagaosa, N. & Tokura, Y. Topological properties and dynamics of magnetic skyrmions. Nature Nanotech. 8, 899–911 (2013).

    Article  CAS  Google Scholar 

  16. Schulz, T. et al. Emergent electrodynamics of skyrmions in a chiral magnet. Nature Phys. 8, 301–304 (2012).

    Article  CAS  Google Scholar 

  17. Yu, X. Z. et al. Skyrmion flow near room temperature in an ultralow current density. Nature Commun. 3, 988 (2012).

    Article  CAS  Google Scholar 

  18. Iwasaki, J., Mochizuki, M. & Nagaosa, N. Universal current–velocity relation of skyrmion motion in chiral magnets. Nature Commun. 4, 1463 (2013).

    Article  Google Scholar 

  19. Onose, Y., Okamura, Y., Seki, S., Ishiwata, S. & Tokura, Y. Observation of magnetic excitations of skyrmion crystal in a helimagnetic insulator Cu2OSeO3 . Phys. Rev. Lett. 109, 037603 (2012).

    Article  CAS  Google Scholar 

  20. Jonietz, F. et al. Spin transfer torques in MnSi at ultralow current densities. Science 330, 1648–1651 (2010).

    Article  CAS  Google Scholar 

  21. Mochizuki, M. et al. Thermally driven ratchet motion of a skyrmion microcrystal and topological magnon Hall effect. Nature Mater. 13, 241–246 (2014).

    Article  CAS  Google Scholar 

  22. White, J. S. et al. Electric field control of the skyrmion lattice in Cu2OSeO3 . J. Phys. Condens. Matter 24, 432201 (2012).

    Article  CAS  Google Scholar 

  23. Fåk, B., Sadykov, R. A., Flouquet, J. & Lapertot, G. Pressure dependence of the magnetic structure of the itinerant electron magnet MnSi. J. Phys. Condens. Matter 17, 1635–1644 (2005).

    Article  Google Scholar 

  24. Ritz, R. et al. Formation of a topological non-Fermi liquid in MnSi. Nature 497, 231–234 (2013).

    Article  CAS  Google Scholar 

  25. Ritz, R. et al. Giant generic topological Hall resistivity of MnSi under pressure. Phys. Rev. B 87, 134424 (2013).

    Article  Google Scholar 

  26. Pedrazzini, P. et al. Metallic state in cubic FeGe beyond its quantum phase transition. Phys. Rev. Lett. 98, 047204 (2007).

    Article  CAS  Google Scholar 

  27. Koretsune, T., Nagaosa, N. & Arita, R. Control of Dzyaloshinskii–Moriya interaction in Mn1−xFexGe: a first-principles study. Preprint at http://arxiv.org/abs/1503.03777 (2015).

  28. Gayles, J. et al. Dzyaloshinskii–Moriya interaction and Hall effects in the skyrmion phase of Mn1−xFexGe alloys. Preprint at http://arxiv.org/abs/1503.04842 (2015).

  29. Richardson, M. The partial equilibrium diagram of the Fe-Ge system in the range 40–72 at. % Ge, and the crystallisation of some iron germanides by chemical transport reactions. Acta Chem. Scand. 21, 2305–2317 (1967).

    Article  CAS  Google Scholar 

  30. Ishizuka, K. & Allman, B. Phase measurement of atomic resolution image using transport of intensity equation. J. Electron Microsc. (Tokyo) 54, 191–197 (2005).

    Google Scholar 

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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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