Fast domain wall motion induced by antiferromagnetic spin dynamics at the angular momentum compensation temperature of ferrimagnets

 · Invited

Abstract

Antiferromagnetic spintronics is an emerging research field which aims to utilize antiferromagnets as core elements in spintronic devices. A central motivation toward this direction is that antiferromagnetic spin dynamics is expected to be much faster than ferromagnetic counterpart because antiferromagnets have higher resonance frequencies than ferromagnets. Recent theories indeed predicted faster dynamics of antiferromagnetic domain walls (DWs) than ferromagnetic DWs. However, experimental investigations of antiferromagnetic spin dynamics have remained unexplored mainly because of the immunity of antiferromagnets to magnetic fields. Furthermore, this immunity makes field-driven antiferromagnetic DW motion impossible despite rich physics of field-driven DW dynamics as proven in ferromagnetic DW studies. Here we show that fast field-driven antiferromagnetic spin dynamics is realized in ferrimagnets at the angular momentum compensation point TA. Using rare-earth–3d-transition metal ferrimagnetic compounds where net magnetic moment is nonzero at TA, the field-driven DW mobility remarkably enhances up to 20 km s−1T−1. The collective coordinate approach generalized for ferrimagnets and atomistic spin model simulations show that this remarkable enhancement is a consequence of antiferromagnetic spin dynamics at TA. Our finding allows us to investigate the physics of antiferromagnetic spin dynamics and highlights the importance of tuning of the angular momentum compensation point of ferrimagnets, which could be a key towards ferrimagnetic spintronics [1].

References
[1] Kab-Jin Kim et al. Nat. Mater. doi:10.1038/nmat4990 (2017).

*K.-J.K. was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIP) (No. 2017R1C1B2009686, NRF-2016R1A5A1008184) and by the DGIST R&D Program of the Ministry of Science, ICT and Future Planning (17-BT-02).

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Presenters

  • Kab-Jin Kim

    • Department of Physics, Korea Advanced Institute of Science and Technology
    • KAIST

Authors

  • Kab-Jin Kim

    • Department of Physics, Korea Advanced Institute of Science and Technology
    • KAIST

  • Se-Kwon Kim

    • Department of Physics and Astronomy, University of California, Los Angeles

  • Yuushou Hirata

    • Institute for Chemical Research, Kyoto University

  • Se-Hyeok Oh

    • Department of Nano-Semiconductor and Engineering, Korea University

  • Takayuki Tono

    • Institute for Chemical Research, Kyoto University

  • Duck-Ho Kim

    • Institute for Chemical Research, Kyoto University

  • Takaya Okuno

    • Institute for Chemical Research, Kyoto University

  • Woo Seung Ham

    • Institute for Chemical Research, Kyoto University

  • Sanghoon Kim

    • Institute for Chemical Research, Kyoto University

  • Gyoungchoon Go

    • Department of Materials Science & Engineering, Korea University

  • Yaroslav Tserkovnyak

    • University of California, Los Angeles
    • Physics, University of California Los Angeles
    • Department of Physics and Astronomy, Univ of California - Los Angeles
    • Physics and Astronomy, University of California, Los Angeles
    • Univ of California - Los Angeles
    • Physics and Astronomy, Univ of California - Los Angeles
    • Physics and Astronomy, University of California Los Angeles
    • Department of Physics and Astronomy, University of California, Los Angeles
    • Physics, Univ of California - Los Angeles
    • Department of Physics and Astronomy, University of California Los Angeles

  • Arata Tsukamoto

    • College of Science and Technology, Nihon University

  • Takahiro Moriyama

    • Institute for Chemical Research, Kyoto University

  • Kyung-Jin Lee

    • Materials Science and Engineering, Korea University
    • Department of Materials Science & Engineering, Korea University
    • Korea University
    • Department of Materials Science and Engineering, Korea University

  • Teruo Ono

    • Institute for Chemical Research, Kyoto University