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Electronic nematic phase and unconventional superconductivity in strong correlated systems

Research Project

Project/Area Number 18J22138
Research Category

Grant-in-Aid for JSPS Fellows

Allocation TypeSingle-year Grants
Section国内
Research Field Condensed matter physics II
Research InstitutionKyoto University
Research Fellow 佐藤 雄貴  京都大学, 理学研究科, 特別研究員(DC1)
Project Period (FY) 2018-04-25 – 2021-03-31
Project Status Completed (Fiscal Year 2020)
Budget Amount *help
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2020: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2019: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2018: ¥900,000 (Direct Cost: ¥900,000)
Keywords超伝導 / FFLO / 電子ネマティック / 近藤絶縁体 / 熱伝導率 / 比熱 / 中性フェルミオン / 電子ネマティック相 / 量子臨界点 / 非フェルミ液体 / 強相関電子系 / 近藤効果 / トポロジカル絶縁体 / 価数揺動 / 低温物性 / 熱伝導 / パルス高磁場
Outline of Annual Research Achievements

当該年度は以下の研究実績を得た。
(1)最高磁場17 T、最低温度0.5 Kまで測定可能な比熱測定システムを立ち上げ、鉄系超伝導体FeSeの比熱を面間磁場下において詳細に測定し、低温高磁場領域において相転移が起こっている熱力学的な証拠を得た。さらに同一の単結晶試料では、STM/STS測定によって試料表面で超伝導のシグナルが臨界磁場よりも低磁場で破壊されていることが観測されており、表面とバルクで異なる超伝導秩序変数が実現していることが示唆される。これらの結果は、FeSeの低温高磁場相においてFFLO状態が実現している強い証拠を与えている。
(2)最近新しく発見された近藤絶縁体YbIr3Si7について、その低エネルギー励起を詳細に調べた。初年度に研究を進めていた近藤絶縁体YbB12が非磁性であったのに対して、YbIr3Si7はネール温度4 K以下で反強磁性秩序を形成し、さらに2.5 T程度の磁場を印加することで別の反強磁性相へと相転移を起こす。熱伝導率を0.1 K程度まで測定した結果、低磁場域ではフェルミオン励起の寄与を与える有限の残留熱伝導率が観測され、この値が荷電粒子について成立するWiedemann-Franzの法則では説明できないほど大きな値をとることが明らかになった。このことは中性フェルミオン励起による熱的金属状態が、近藤絶縁体の多くの系で広く存在していることを示唆している。さらに高磁場の反強磁性相では熱伝導率が急激に0に向かう様子が観測され、熱的絶縁相が実現していることが分かった。本成果は、中性フェルミオンが系の磁性と密接に関係しているという新しい知見を与えるものである。

Research Progress Status

令和2年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和2年度が最終年度であるため、記入しない。

Report

(3 results)
  • 2020 Annual Research Report
  • 2019 Annual Research Report
  • 2018 Annual Research Report

Research Products

(22 results)

All 2021 2020 2019 2018 Other

All Int'l Joint Research (8 results) Journal Article (8 results) (of which Int'l Joint Research: 5 results,  Peer Reviewed: 7 results,  Open Access: 4 results) Presentation (6 results) (of which Int'l Joint Research: 2 results)

  • [Int'l Joint Research] Radboud University(オランダ)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] University of Bristol(英国)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] Technische Universitat Dresden(ドイツ)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] University of California, Berkeley/University of Michigan/Los Alamos National Laboratory(米国)

    • Related Report
      2018 Annual Research Report
  • [Int'l Joint Research] Radbound University(オランダ)

    • Related Report
      2018 Annual Research Report
  • [Int'l Joint Research] Universite Chretienne Bilingue du Congo(コンゴ共和国)

    • Related Report
      2018 Annual Research Report
  • [Int'l Joint Research] Nanjing University(中国)

    • Related Report
      2018 Annual Research Report
  • [Int'l Joint Research] University of Oxford(英国)

    • Related Report
      2018 Annual Research Report
  • [Journal Article] Quantum Oscillations and Charge Neutral Fermions in Kondo Insulators2021

    • Author(s)
      佐藤 雄貴、笠原 裕一、伊賀 文俊、松田 祐司
    • Journal Title

      Butsuri

      Volume: 76 Issue: 2 Pages: 87-92

    • DOI

      10.11316/butsuri.76.2_87

    • NAID

      130007981337

    • ISSN
      0029-0181, 2423-8872
    • Year and Date
      2021-02-05
    • Related Report
      2020 Annual Research Report
  • [Journal Article] Bond Directional Anapole Order in a Spin-Orbit Coupled Mott Insulator Sr2(Ir1-xRhx)O42021

    • Author(s)
      H. Murayama, K. Ishida, R. Kurihara, T. Ono, Y. Sato, Y. Kasahara, H. Watanabe, Y. Yanase, G. Cao, Y. Mizukami, T. Shibauchi, Y. Matsuda, and S. Kasahara
    • Journal Title

      Phys. Rev. X

      Volume: 11 Issue: 1 Pages: 011021-011021

    • DOI

      10.1103/physrevx.11.011021

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Unusual high-field metal in a Kondo insulator2021

    • Author(s)
      Xiang Z.、Chen L.、Chen K.-W.、Tinsman C.、Sato Y.、Asaba T.、Lu H.、Kasahara Y.、Jaime M.、Balakirev F.、Iga F.、Matsuda Y.、Singleton J.、Li L.
    • Journal Title

      Nature Physics

      Volume: -

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Non-Fermi Liquid Transport in the Vicinity of the Nematic Quantum Critical Point of Superconducting FeSe1-xSx2020

    • Author(s)
      W. K. Huang, S. Hosoi, M. Culo, S. Kasahara, Y. Sato, K. Matsuura, Y. Mizukami, M. Berben, N. E. Hussey, H. Kontani, T. Shibauchi, and Y. Matsuda
    • Journal Title

      Phys. Rev. Res.

      Volume: 2 Issue: 3 Pages: 033367-033367

    • DOI

      10.1103/physrevresearch.2.033367

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Presence and absence of itinerant gapless excitations in the quantum spin liquid candidate EtMe3Sb[Pd(dmit)2]22020

    • Author(s)
      Yamashita M.、Sato Y.、Tominaga T.、Kasahara Y.、Kasahara S.、Cui H.、Kato R.、Shibauchi T.、Matsuda Y.
    • Journal Title

      Physical Review B

      Volume: 101 Issue: 14 Pages: 140407-140407

    • DOI

      10.1103/physrevb.101.140407

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Evidence for an FFLO State with Segmented Vortices in the BCS-BEC-Crossover Superconductor FeSe2020

    • Author(s)
      S. Kasahara, Y. Sato, S. Licciardello, M. Culo, S. Arsenijevic, T. Ottenbros, T. Tominaga, J. Boker, I. Eremin, T. Shibauchi, J. Wosnitza, N. E. Hussey, and Y. Matsuda,
    • Journal Title

      Phys. Rev. Lett.

      Volume: 124 Issue: 10 Pages: 107001-107001

    • DOI

      10.1103/physrevlett.124.107001

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Effect of quenched disorder on the quantum spin liquid state of the triangular-lattice antiferromagnet 1T?TaS22020

    • Author(s)
      Murayama H.、Sato Y.、Taniguchi T.、Kurihara R.、Xing X. Z.、Huang W.、Kasahara S.、Kasahara Y.、Kimchi I.、Yoshida M.、Iwasa Y.、Mizukami Y.、Shibauchi T.、Konczykowski M.、Matsuda Y.
    • Journal Title

      Physical Review Research

      Volume: 2 Issue: 1 Pages: 013099-013099

    • DOI

      10.1103/physrevresearch.2.013099

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Quantum oscillations of electrical resistivity in an insulator2018

    • Author(s)
      Xiang Z.、Kasahara Y.、Asaba T.、Lawson B.、Tinsman C.、Chen Lu、Sugimoto K.、Kawaguchi S.、Sato Y.、Li G.、Yao S.、Chen Y. L.、Iga F.、Singleton John、Matsuda Y.、Li Lu
    • Journal Title

      Science

      Volume: 362 Issue: 6410 Pages: 65-69

    • DOI

      10.1126/science.aap9607

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Presentation] 近藤絶縁体YbIr3Si7における中性フェルミオンと その磁場誘起不安定性2021

    • Author(s)
      佐藤雄貴
    • Organizer
      日本物理学会
    • Related Report
      2020 Annual Research Report
  • [Presentation] Gapless neutral fermions in insulating YbIr3Si7 revealed by specific heat and thermal conductivity2021

    • Author(s)
      Yuki Sato
    • Organizer
      American Physical Society March Meeting
    • Related Report
      2020 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 比熱測定でみた近藤絶縁体 YbIr3Si7の低エネルギー励起2020

    • Author(s)
      佐藤雄貴
    • Organizer
      日本物理学会
    • Related Report
      2020 Annual Research Report
  • [Presentation] 微細加工したトポロジカル 近藤絶縁体 YbB12の輸送現象測定2019

    • Author(s)
      佐藤雄貴
    • Organizer
      日本物理学会
    • Related Report
      2019 Annual Research Report
  • [Presentation] Quantum oscillations and charge neutral fermions in topological Kondo insulator YbB122019

    • Author(s)
      Yuki Sato
    • Organizer
      日本物理学会
    • Related Report
      2019 Annual Research Report
  • [Presentation] Charge neutral fermions and quantum oscillations in a topological Kondo Insulator YbB122019

    • Author(s)
      Yuki Sato
    • Organizer
      American Physical Society, March Meeting, Boston
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research

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Published: 2018-05-01   Modified: 2021-12-27  

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