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Universal helimagnon and skyrmion excitations in metallic, semiconducting and insulating chiral magnets

Nature Materials volume 14, pages 478–483 (2015)Cite this article

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Abstract

Nearly seven decades of research on microwave excitations of magnetic materials have led to a wide range of applications in electronics1,2,3,4. The recent discovery of topological spin solitons in chiral magnets, so-called skyrmions5,6,7,8,9, promises high-frequency devices that exploit the exceptional emergent electrodynamics of these compounds10,11,12,13,14. Therefore, an accurate and unified quantitative account of their resonant response is key. Here, we report all-electrical spectroscopy of the collective spin excitations in the metallic, semiconducting and insulating chiral magnets MnSi, Fe1−xCoxSi and Cu2OSeO3, respectively, using broadband coplanar waveguides. By taking into account dipolar interactions, we achieve a precise quantitative modelling across the entire magnetic phase diagrams using two material-specific parameters that quantify the chiral and the critical field energy. The universal behaviour sets the stage for purpose-designed applications based on the resonant response of chiral magnets with tailored electric conductivity and an unprecedented freedom for an integration with electronics.

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Figure 1: Spin textures of cubic chiral helimagnets and their collective excitations.
Figure 2: All-electrical broadband spectroscopy data of metallic, semiconducting and insulating cubic chiral helimagnets.
Figure 3: Comparison of calculated and measured excitation spectra for the different helimagnets and shapes.

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References

  1. Snoek, J. L. Gyromagnetic resonance in ferrites. Nature 160, 90 (1947).

    Article  CAS  Google Scholar 

  2. Kittel, C. On the theory of ferromagnetic resonance absorption. Phys. Rev. 73, 155–161 (1948).

    Article  CAS  Google Scholar 

  3. Gurevich, A. G. & Melkov, G. A. Magnetization Oscillations and Waves (CRC Press, 1996).

    Google Scholar 

  4. Kruglyak, V. V., Demokritov, S. O. & Grundler, D. Magnonics. J. Phys. D 43, 264001 (2010).

    Article  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 (2010).

    Article  Google Scholar 

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

    Article  CAS  Google Scholar 

  8. 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 

  9. Milde, P. et al. Unwinding of a skyrmion lattice by magnetic monopoles. Science 340, 1076–1080 (2013).

    Article  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

  13. Fert, A., Cros, V. & Sampaio, J. Skyrmions on the track. Nature Nano. 8, 152–156 (2013).

    Article  CAS  Google Scholar 

  14. Zhang, X. et al. Magnetic skyrmion logic gates: Conversion, duplication and merging of skyrmions. Preprint at http://arxiv.org/abs/1410.3086 (2014)

  15. Baryakhtar, V. G. & Ivanov, B. A. Phase diagram of a ferromagnetic plate in an external magnetic field. Sov. Phys. JETP 45, 789–796 (1977).

    Google Scholar 

  16. Gubbiotti, G. et al. Spin waves in perpendicularly magnetized Co/Ni(111) multilayers in the presence of magnetic domains. Phys. Rev. B 86, 014401 (2012).

    Article  Google Scholar 

  17. Lenk, B., Ulrichs, H., Garbs, F. & Münzenberg, M. The building blocks of magnonics. Phys. Rep. 507, 107–136 (2011).

    Article  Google Scholar 

  18. Duerr, G., Thurner, K., Topp, J., Huber, R. & Grundler, D. Enhanced transmission through squeezed modes in a self-cladding magnonic waveguide. Phys. Rev. Lett. 108, 227202 (2012).

    Article  CAS  Google Scholar 

  19. Topp, J., Podbielski, J., Heitmann, D. & Grundler, D. Internal spin-wave confinement in magnetic nanowires due to zig-zag shaped magnetization. Phys. Rev. B 78, 024431 (2008).

    Article  Google Scholar 

  20. Ishikawa, Y., Noda, Y., Uemura, Y. J., Majkrzak, C. F. & Shirane, G. Paramagnetic spin fluctuations in the weak itinerant-electron ferromagnet MnSi. Phys. Rev. B 31, 5884–5893 (1985).

    Article  CAS  Google Scholar 

  21. Janoschek, M. et al. Helimagnon bands as universal excitations of chiral magnets. Phys. Rev. B 81, 214436 (2010).

    Article  Google Scholar 

  22. 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 

  23. Kataoka, M. Spin waves in systems with long period helical spin density waves due to the antisymmetric and symmetric exchange interactions. J. Phys. Soc. Jpn 56, 3635–3647 (1987).

    Article  Google Scholar 

  24. Date, M., Okuda, K. & Kadowaki, K. Electron-spin resonance in the itinerant-electron helical magnet MnSi. J. Phys. Soc. Jpn 42, 1555–1561 (1977).

    Article  CAS  Google Scholar 

  25. Koralek, J. D. et al. Observation of coherent helimagnons and Gilbert damping in an itinerant magnet. Phys. Rev. Lett. 109, 247204 (2012).

    Article  CAS  Google Scholar 

  26. Mochizuki, M. Spin-wave modes and their intense excitation effects in skyrmion crystals. Phys. Rev. Lett. 108, 017601 (2012).

    Article  Google Scholar 

  27. Okamura, Y. et al. Microwave magnetoelectric effect via skyrmion resonance modes in a helimagnetic multiferroic. Nature Commun. 4, 2391 (2013).

    Article  CAS  Google Scholar 

  28. Vlaminck, V. & Bailleul, M. Current-induced spin-wave doppler shift. Science 322, 410–413 (2008).

    Article  CAS  Google Scholar 

  29. Yu, H. et al. Omnidirectional spin-wave nanograting coupler. Nature Commun. 4, 2702 (2013).

    Article  Google Scholar 

  30. Bauer, A. & Pfleiderer, C. Magnetic phase diagram of MnSi inferred from magnetization and ac susceptibility. Phys. Rev. B 85, 214418 (2012).

    Article  Google Scholar 

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

    Article  CAS  Google Scholar 

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Acknowledgements

We wish to thank P. Böni, K. Everschor, M. Mochizuki, N. Nagaosa, S. Mayr and, in particular, A. Rosch for helpful discussions and support. A.B. acknowledges financial support through the TUM Graduate School. Financial support through DFG TRR80, SFB608, German Excellence Cluster Nanosystems Initiative Munich, and ERC-AdG (291079 TOPFIT) is gratefully acknowledged.

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Authors and Affiliations

  1. Physik Department, Lehrstuhl für Physik funktionaler Schichtsysteme, Technische Universität München, D-85748 Garching, Germany

    T. Schwarze, I. Stasinopoulos & D. Grundler

  2. Institute of Theoretical Physics, University of Cologne, D-50937 Cologne, Germany

    J. Waizner & M. Garst

  3. Physik Department, Lehrstuhl für Topologie korrelierter Systeme, Technische Universität München, D-85748 Garching, Germany

    A. Bauer & C. Pfleiderer

  4. Institut de Physique de la Matiére Complexe, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland

    H. Berger

  5. Institut des Matériaux, Faculté Sciences et Technique de l’Ingénieur, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland

    D. Grundler

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  1. T. Schwarze
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  8. D. Grundler
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Contributions

T.S. and D.G. developed the experimental set-up and performed the experiments; T.S., J.W., M.G., A.B. and I.S. analysed the experimental data; A.B. grew the MnSi and Fe1−xCoxSi single crystals and characterized them; H.B. grew the Cu2OSeO3 single crystals and characterized them; J.W. and M.G. developed the theoretical interpretation; D.G. supervised the experimental work; D.G. and C.P. proposed this study; T.S., A.B., M.G., C.P. and D.G. wrote the manuscript; all authors discussed the data and commented on the manuscript.

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Correspondence to M. Garst or D. Grundler.

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The authors declare no competing financial interests.

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Schwarze, T., Waizner, J., Garst, M. et al. Universal helimagnon and skyrmion excitations in metallic, semiconducting and insulating chiral magnets. Nature Mater 14, 478–483 (2015). https://doi.org/10.1038/nmat4223

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