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Elucidation and control of topological order in quantum spin liquids

Research Project

Project/Area Number 21K13881
Research Category

Grant-in-Aid for Early-Career Scientists

Allocation TypeMulti-year Fund
Review Section Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
Research InstitutionKyoto University

Principal Investigator

Suetsugu Shota  京都大学, 理学研究科, 助教 (00893710)

Project Period (FY) 2021-04-01 – 2023-03-31
Project Status Completed (Fiscal Year 2022)
Budget Amount *help
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2022: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Fiscal Year 2021: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
Keywords量子スピン液体 / トポロジー
Outline of Research at the Start

局在スピンが絶対零度においても秩序化・凍結せずに揺らいでいる状態を量子スピン液体と呼ぶ。その中でも量子スピン液体状態を基底状態として持つキタエフ模型は、局在スピンがマヨラナ粒子に分数化するため非可換エニオンなどのマヨラナ粒子によるトポロジカル励起を探索する格好の舞台となっている。
本研究ではキタエフ型量子スピン液体候補物質であるα-RuCl3において、磁気トルク・熱伝導度の磁場角度依存性を調べ、キタエフ模型のトポロジカル相を解明する。本研究を通じて、電子相関の効果で生じるトポロジーの研究を、トポロジカル相制御下におけるトポロジカル励起探索の段階へと進展させる。

Outline of Final Research Achievements

Quantum spin liquids, in which localized spins fluctuate without magnetic order or spin freezing even at absolute zero temperature, have attracted much attention because the localized spins fractionalized into different degrees of freedom, such as Majorana fermions. Although α-RuCl3 is known as a candidate material for the quantum spin liquid, it has been controversial whether the quantum spin liquid state is actually realized or not. In this project, we have demonstrated the existence of a first-order phase transition in a magnetic field by the specific heat and thermal conductivity experiments on α-RuCl3. Our results indicate the presence of the quantum spin liquid phase in α-RuCl3.

Academic Significance and Societal Importance of the Research Achievements

量子スピン液体状態で現れるマヨラナ粒子は環境ノイズに強いトポロジカル量子計算の実現に必要なため注目を集めている。本研究ではその候補物質であるα-RuCl3において確かに量子スピン液体状態が実現していることを示し、これまでの論争に決着をつけた。以上の研究成果により量子スピン液体状態の存在が確立されたため、今後はマヨラナ粒子を探索する研究がさらに加速することが期待される。

Report

(3 results)
  • 2022 Annual Research Report   Final Research Report ( PDF )
  • 2021 Research-status Report
  • Research Products

    (6 results)

All 2023 2022

All Journal Article (3 results) (of which Peer Reviewed: 3 results,  Open Access: 2 results) Presentation (3 results) (of which Int'l Joint Research: 2 results)

  • [Journal Article] Evidence for a Phase Transition in the Quantum Spin Liquid State of a Kitaev Candidate α-RuCl32022

    • Author(s)
      Suetsugu Shota、Ukai Yuzuki、Shimomura Masaki、Kamimura Masashi、Asaba Tomoya、Kasahara Yuichi、Kurita Nobuyuki、Tanaka Hidekazu、Shibauchi Takasada、Nasu Joji、Motome Yukitoshi、Matsuda Yuji
    • Journal Title

      Journal of the Physical Society of Japan

      Volume: 91 Issue: 12 Pages: 124703-124703

    • DOI

      10.7566/jpsj.91.124703

    • Related Report
      2022 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Quantized and unquantized thermal Hall conductance of the Kitaev spin liquid candidate α-RuCl32022

    • Author(s)
      Kasahara Y.、Suetsugu S.、Asaba T.、Kasahara S.、Shibauchi T.、Kurita N.、Tanaka H.、Matsuda Y.
    • Journal Title

      Physical Review B

      Volume: 106 Issue: 6

    • DOI

      10.1103/physrevb.106.l060410

    • Related Report
      2022 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Intrinsic suppression of the topological thermal Hall effect in an exactly solvable quantum magnet2022

    • Author(s)
      S. Suetsugu, T. Yokoi, K. Totsuka, T. Ono, I. Tanaka, S. Kasahara, Y. Kasahara, Z. Chengchao, H. Kageyama, and Y. Matsuda
    • Journal Title

      Physical Review B

      Volume: 105 Issue: 2 Pages: 024415-024415

    • DOI

      10.1103/physrevb.105.024415

    • Related Report
      2021 Research-status Report
    • Peer Reviewed
  • [Presentation] Fully gapped pairing states in spin-triplet superconductor UTe22023

    • Author(s)
      Shota Suetsugu, M. Shimomura, M. Kamimura, T. Asaba, H. Asaeda, Y. Kosuge, Y. Sekino, S. Ikemori, Y. Kasahara, Y. Kohsaka, M. Lee, Y. Yanase, H. Sakai, P. Opletal, Y. Tokiwa, Y. Haga, and Y. Matsuda
    • Organizer
      APS March Meeting 2023
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Fully gapped pairing states in spin-triplet superconductor UTe22022

    • Author(s)
      Shota Suetsugu, M. Shimomura, M. Kamimura, T. Asaba, H. Asaeda, Y. Kosuge, Y. Sekino, S. Ikemori, Y. Kasahara, Y. Kohsaka, Y. Yanase, H. Sakai, P. Opletal, Y. Tokiwa, Y. Haga, and Y. Matsuda
    • Organizer
      非自明な電子状態で発現する超伝導現象の新しい潮流
    • Related Report
      2022 Annual Research Report
  • [Presentation] Field-induced first-order topological phase transition in a Kitaev spin liquid candidate α-RuCl32022

    • Author(s)
      S. Suetsugu, Y. Ukai, M. Shimomura, M. Kamimura, T. Asaba, Y. Kasahara, N. Kurita, H. Tanaka, T. Shibauchi, J. Nasu, Y. Motome, Y. Matsuda
    • Organizer
      APS March meeting 2022
    • Related Report
      2021 Research-status Report
    • Int'l Joint Research

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Published: 2021-04-28   Modified: 2024-01-30  

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