Details of the Researcher

PHOTO

Soma Miki
Section
Advanced Institute for Materials Research
Job title
Assistant Professor
Degree

  • 博士（工学）（大阪大学）

  • 修士（工学）（大阪大学）

Research History 2

  • 2024/09 - Present
    Tohoku University　Advanced Institute for Materials Research　assistant professor

  • 2023/10 - 2024/08
    Osaka University　Graduate School of Engineering Science　assistant professor

Education 3

  • Osaka University　Graduate School of Engineering Science　Department of Materials Engineering Science Division of Materials Physics

    2021/04 - 2023/09

  • Osaka University　Graduate School of Engineering Science　Department of Materials Engineering Science Division of Materials Physics

    2019/04 - 2021/03

  • Osaka University

    2015/04 - 2019/03

Professional Memberships 3

  • 日本磁気学会

    2022/06 - Present

  • 日本応用物理学会

    2019/07 - Present

  • 日本物理学会

    2018/12 - Present

Research Interests 5

  • ブラウン運動

  • 電圧制御

  • 磁気スキルミオン

  • 磁性

  • スピントロニクス

Research Areas 3

  • Nanotechnology/Materials / Metallic materials /

  • Nanotechnology/Materials / Applied materials /

  • Natural sciences / Magnetism, superconductivity, and strongly correlated systems /

Awards 1

  1. 学生講演賞（桜井講演賞）

    2024/01　日本磁気学会　磁気スキルミオンのブラウン運動におけるカイラルな回転のポラリティ依存性

Papers 8

  1. Transfer entropy and flow of information in two-skyrmion system

    Tenta Tani, Soma Miki, Hiroki Mori, Minori Goto, Yoshishige Suzuki, Eiiti Tamura

    2024/12/25

    More details Close

    We theoretically investigate the flow of information in an interacting two-skyrmion system confined in a box at finite temperature. Using numerical simulations based on the Thiele-Langevin equation, we demonstrate that the skyrmion motion cannot be fully described by the master equation, highlighting the system's simplicity with its nontrivial dynamics. Particularly, due to the chiral motion of skyrmion, we find asymmetric flow of information even in equilibrium, which is demonstrated by the violation of the detailed balance condition. We analyze this novel system using information-theoretical quantities including Shannon entropy, mutual information, and transfer entropy. By the analyses, the physical significance of transfer entropy as a measure of flow of information, which has been overlooked in previous studies, is elucidated. Notably, the peak position of the transfer entropy, as a function of time delay, is found to be independent of the interaction range between the two skyrmions yet dependent on the box size. This peak corresponds to the characteristic time required for changing the skyrmion state: the box size divided by the average velocity of skyrmions. We can understand that the information transmission time consists of the time to obtain mutual information and the time to write the information. Since the unusual asymmetric circulation of information is revealed in this two-skyrmion system, it can be a unique platform for future applications to natural computing using flow of information, including more efficient machine learning algorithm.

  2. Hysteresis-free voltage gating of the skyrmion

    Mikito Kasagawa, Soma Miki, Ken Tanaka Hashimoto, Akifumi Shimmura, Ryo Ishikawa, Yoichi Shiota, Minori Goto, Hikaru Nomura, Yoshishige Suzuki

    Applied Physics Letters　2024/03/18

    DOI： 10.1063/5.0192981 　

  3. Spatial control of skyrmion stabilization energy by low-energy Ga+ ion implantation

    S. Miki, K. Hashimoto, J. Cho, J. Jung, C. Y. You, R. Ishikawa, E. Tamura, H. Nomura, M. Goto, Y. Suzuki

    Applied Physics Letters　2023/05/15

    DOI： 10.1063/5.0153768 　

  4. Size-independent drive of one-dimensional skyrmion motion using exchange energy control

    Soma Miki, Eiiti Tamura, Hikaru Nomura, Minori Goto, Yoshishige Suzuki

    Journal of the Physical Society of Japan　90　(11)　2021/11/15

    DOI： 10.7566/JPSJ.90.114703 　

    ISSN： 0031-9015

    eISSN： 1347-4073

  5. Diffusion of a magnetic skyrmion in two-dimensional space

    Yoshishige Suzuki, Soma Miki, Yusuke Imai, Eiiti Tamura

    Physics Letters, Section A: General, Atomic and Solid State Physics　413　2021/10/18

    DOI： 10.1016/j.physleta.2021.127603 　

    ISSN： 0375-9601

  6. Brownian motion of magnetic skyrmions in one- And two-dimensional systems

    Soma Miki, Yuma Jibiki, Eiiti Tamura, Minori Goto, Mikihiko Oogane, Jaehun Cho, Ryo Ishikawa, Hikaru Nomura, Yoshishige Suzuki

    Journal of the Physical Society of Japan　90　(8)　2021/08/15

    DOI： 10.7566/JPSJ.90.083601 　

    ISSN： 0031-9015

    eISSN： 1347-4073

  7. Manipulating 1-dimensional skyrmion motion by the external magnetic field gradient

    Jaehun Cho, Eiiti Tamura, Chaozhe Liu, Soma Miki, Chun Yeol You, June Seo Kim, Hikaru Nomura, Minori Goto, Ryoichi Nakatani, Yoshishige Suzuki

    New Journal of Physics　22　(10)　2020/10

    DOI： 10.1088/1367-2630/abbead 　

    ISSN： 1367-2630

  8. Skyrmion Brownian circuit implemented in continuous ferromagnetic thin film

    Yuma Jibiki, Minori Goto, Eiiti Tamura, Jaehun Cho, Soma Miki, Ryo Ishikawa, Hikaru Nomura, Titiksha Srivastava, Willy Lim, Stephane Auffret, Claire Baraduc, Helene Bea, Yoshishige Suzuki

    Applied Physics Letters　117　(8)　2020/08/24

    DOI： 10.1063/5.0011105 　

    ISSN： 0003-6951

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Misc. 2

  1. Brownian computing by magnetic skyrmions

    MIKI Soma, ISHIKAWA Ryo, GOTO Minori

    Oyo Buturi　94　(4)　197-201　2025/04/01

    Publisher: The Japan Society of Applied Physics

    DOI： 10.11470/oubutsu.94.4_197 　

    ISSN： 0369-8009

    eISSN： 2188-2290

    More details Close

    The energy consumption associated with recent artificial intelligence has become even more critical. A new device to solve this problem, stochastic computing using room-temperature heat, has been proposed and demonstrated in spintronics by tuning the magnetic device and daring the spins to be susceptible to thermal fluctuations. Magnetic skyrmions, which are spin structures in magnetic thin films, behave as particles and exhibit thermal fluctuations of spins as Brownian motion in solid. This article introduces a “Brownian computer” that requires little external energy by the Brownian motion and describes the properties of Brownian motion of magnetic skyrmions and its control.

  2. Development of Magnetic Skyrmion Control Methods for Unconventional Computing

    石川諒, 三木颯馬

    まぐね　18　(5)　2023

    ISSN： 1880-7208

Research Projects 2

  1. voltage control of magnetic skyrmion helicity and its direct observation

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Research Activity Start-up

    Institution: Osaka University

    2024/07/31 - 2026/03/31

  2. High-speed measurement of magnetic skyrmion motion and detection of its mass

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for JSPS Fellows

    Institution: Osaka University

    2023/04/25 - 2025/03/31