Abstract

In the presence of a magnetic field, the flow of charged particles in a conductor is deflected from the direction of the applied force, which gives rise to the ordinary Hall effect. Analogously, moving skyrmions with non-zero topological charges and finite fictitious magnetic fields exhibit the skyrmion Hall effect, which is detrimental for applications such as skyrmion racetrack memory. It was predicted that the skyrmion Hall effect vanishes for antiferromagnetic skyrmions because their fictitious magnetic field, proportional to net spin density, is zero. Here we investigate the current-driven transverse elongation of pinned ferrimagnetic bubbles. We estimate the skyrmion Hall effect from the angle between the current and the bubble elongation directions. The angle and, hence, the skyrmion Hall effect vanishes at the angular momentum compensation temperature where the net spin density vanishes. Furthermore, our study establishes a direct connection between the fictitious magnetic field and the spin density.

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Acknowledgements

This work was supported by the JSPS KAKENHI (grant nos 15H05702, 26103002 and 26103004), Collaborative Research Program of the Institute for Chemical Research, Kyoto University, and R&D project for the ICT Key Technology of MEXT from the Japan Society for the Promotion of Science (JSPS). This work was partly supported by the Cooperative Research Project Program of the Research Institute of Electrical Communication, Tohoku University. D.-H.K. was supported as an Overseas Researcher under the Postdoctoral Fellowship of JSPS (grant no. P16314). D.-K.L., S.-H.O. and K.-J.L. were supported by the National Research Foundation of Korea (grant no. 2017R1A2B2006119), Samsung Research Funding Center of Samsung Electronics under project no. SRFCMA1702-02 and the KIST Institutional Program (project no. 2V05750). S.K.K. and Y.T. were supported by the Army Research Office under contract no. W911NF-14-1-0016. D.-Y.K. and S.-B.C. were supported by a National Research Foundations of Korea (NRF) grant funded by the Ministry of Science, ICT and Future Planning of Korea (MSIP) (grant nos //2015R1A2A1A05001698 and 2015M3D1A1070465).

Author information

Affiliations

  1. Institute for Chemical Research, Kyoto University, Kyoto, Japan

    • Yuushou Hirata
    • , Duck-Ho Kim
    • , Tomoe Nishimura
    • , Takaya Okuno
    • , Yoichi Shiota
    • , Takahiro Moriyama
    •  & Teruo Ono
  2. Department of Physics and Astronomy, University of California Los Angeles, California, CA, USA

    • Se Kwon Kim
    •  & Yaroslav Tserkovnyak
  3. Department of Physics and Astronomy, University of Missouri, Columbia, MO, USA

    • Se Kwon Kim
  4. Department of Materials Science & Engineering, Korea University, Seoul, Republic of Korea

    • Dong-Kyu Lee
    •  & Kyung-Jin Lee
  5. Department of Nano-Semiconductor and Engineering, Korea University, Seoul, Republic of Korea

    • Se-Hyeok Oh
    •  & Kyung-Jin Lee
  6. Department of Physics and Institute of Applied Physics, Seoul National University, Seoul, Republic of Korea

    • Dae-Yun Kim
    •  & Sug-Bong Choe
  7. College of Science and Technology, Nihon University, Funabashi, Japan

    • Yasuhiro Futakawa
    • , Hiroki Yoshikawa
    •  & Arata Tsukamoto
  8. KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Republic of Korea

    • Kyung-Jin Lee
  9. Center for Spintronics Research Network (CSRN), Graduate School of Engineering Science, Osaka University, Osaka, Japan

    • Teruo Ono

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Contributions

K.-J.L., D.-H.K. and T.Ono planned and designed the experiment. Y.F., H.Y. and A.T. prepared the GdFeCo ferrimagnetic films and Y.H. prepared the devices. Y.H., D.-H.K., D.-Y.K. and T.N. carried out the measurement. S.K.K., K.-J.L. and Y.T. provided theory. D.-H.K. and Y.H. performed the analysis of experimental results. D.-K.L., S.-H.O. and K.-J.L. performed the numerical simulation. D.-H.K., K.-J.L., S.K.K., Y.H., S.-B.C. and T.Ono wrote the manuscript. All the authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing interests.

Corresponding authors

Correspondence to Duck-Ho Kim or Kyung-Jin Lee or Teruo Ono.

Supplementary information

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DOI

https://doi.org/10.1038/s41565-018-0345-2