Letter | Published:

Soliton-like magnetic domain wall motion induced by the interfacial Dzyaloshinskii–Moriya interaction

Nature Physics volume 12, pages 157161 (2016) | Download Citation

Abstract

Topological defects such as magnetic solitons, vortices and skyrmions have started to play an important role in modern magnetism because of their extraordinary stability1, which can be exploited in the production of memory devices. Recently, a type of antisymmetric exchange interaction, namely the Dzyaloshinskii–Moriya interaction (DMI; refs 2,3), has been uncovered and found to influence the formation of topological defects4,5,6,7. Exploring how the DMI affects the dynamics of topological defects is therefore an important task. Here we investigate the dynamics of the magnetic domain wall (DW) under a DMI by developing a real time DW detection scheme. For a weak DMI, the DW velocity increases with the external field and reaches a peak velocity at a threshold field, beyond which it abruptly decreases. For a strong DMI, on the other hand, the velocity reduction is completely suppressed and the peak velocity is maintained constant even far above the threshold field. Such a distinct trend of the velocity can be explained in terms of a magnetic soliton, the topology of which is protected during its motion. Our results therefore shed light on the physics of dynamic topological defects, which paves the way for future work in topology-based memory applications.

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Acknowledgements

We thank H. Tanigawa, T. Suzuki and E. Kariyada for providing us with high-quality Co/Ni films. This work was partly supported by JSPS KAKENHI Grant Numbers 15H05702, 26870300, 26870304, 26103002, 26390008, 25 4251, Collaborative Research Program of the Institute for Chemical Research, Kyoto University, and R&D Project for ICT Key Technology of MEXT from the Japan Society for the Promotion of Science (JSPS).

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Affiliations

  1. Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan

    • Yoko Yoshimura
    • , Kab-Jin Kim
    • , Takuya Taniguchi
    • , Takayuki Tono
    • , Kohei Ueda
    • , Ryo Hiramatsu
    • , Takahiro Moriyama
    •  & Teruo Ono
  2. University of Electro-communications, Chofu, Tokyo 182-8585, Japan

    • Keisuke Yamada
    •  & Yoshinobu Nakatani

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Contributions

T.O. and K.-J.K. planned and supervised the study. Y.Y., K.-J.K., T.Taniguchi, T.Tono, K.U. and R.H. designed the experimental set-up. Y.Y. fabricated the devices, performed the experiment, and collected data. K.Y. and Y.N. performed the simulation. Y.Y., K.-J.K., T.O., K.Y. and Y.N. analysed the data. Y.Y., K.-J.K., T.M. and T.O. wrote the manuscript. All authors discussed the results.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Kab-Jin Kim or Teruo Ono.

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https://doi.org/10.1038/nphys3535

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