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NMR investigation of a strongly-correlated Dirac electron system in the quantum limit of an organic conductor

Research Project

Project/Area Number 17K14330
Research Category

Grant-in-Aid for Young Scientists (B)

Allocation TypeMulti-year Fund
Research Field Condensed matter physics II
Research InstitutionTohoku University

Principal Investigator

Hirata Michihiro  東北大学, 金属材料研究所, 助教 (20776413)

Research Collaborator KOBAYASHI akito  
MATSUNO genki  
OHKI daigo  
KANODA kazushi  
MIYAGAWA kazuya  
ISHIKAWA kyouhei  
BERTHIER claude  
TAMURA masafumi  
Project Period (FY) 2017-04-01 – 2019-03-31
Project Status Completed (Fiscal Year 2018)
Budget Amount *help
¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2017: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
Keywordsディラック電子 / 強相関 / エキシトニック不安定性 / 核磁気共鳴 / 有機導体 / スピンゆらぎ / エキシトニック / 不安定性 / NMR / ディラックコーン / 自発的質量獲得機構 / 分子性固体
Outline of Final Research Achievements

In this study we focused on an unusual electronic state of matter in solids known as the massless Dirac electrons which is characterized by special electrons possessing no effective mass, in marked contrast to conventional massive electrons in ordinary solids. Using an organic salt as a target material, we have experimentally investigated and theoretically examined the impact of strong electronic interactions between massless Dirac electrons. By combining numerical model calculations with nuclear magnetic resonance experiments, we demonstrated that these strong interactions lead to anomalous fluctuations that develop as a precursor to an excitonic transition from massless to massive electronic state.

Academic Significance and Societal Importance of the Research Achievements

本研究は、長らく検証が困難であったディラック電子間の強い相互作用の効果を実験的に初めて検証することに成功した先駆的な仕事であり、相互作用の直接的帰結である新規ゆらぎの発見とそのメカニズムの実験および理論的解明を世界に先駆け達成した画期的な成果である。これは核磁気共鳴と有機物質を組み合わせる他に類を見ない独創的なアプローチと国際的な共同研究が生んだ顕著な成果であり、国内外の学術界に大きなインパクトと派生研究をもたらした点で大きな意義をもつ研究である。

Report

(3 results)
  • 2018 Annual Research Report   Final Research Report ( PDF )
  • 2017 Research-status Report
  • Research Products

    (25 results)

All 2019 2018 2017 Other

All Int'l Joint Research (2 results) Journal Article (2 results) (of which Int'l Joint Research: 1 results,  Peer Reviewed: 2 results) Presentation (18 results) (of which Int'l Joint Research: 8 results,  Invited: 1 results) Remarks (3 results)

  • [Int'l Joint Research] CNRS(フランス)

    • Related Report
      2018 Annual Research Report
  • [Int'l Joint Research] 国立科学研究センター(CNRS)/グルノーブル強磁場研究所(LNCMI-G)(フランス)

    • Related Report
      2017 Research-status Report
  • [Journal Article] 有機物質のディラックコーンにおける強相関効果2018

    • Author(s)
      平田 倫啓
    • Journal Title

      日本物理学会誌, 最近の研究から

      Volume: 73 Pages: 214-220

    • NAID

      130007590578

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Anomalous spin correlations and excitonic instability of interacting 2D Weyl fermions2017

    • Author(s)
      Hirata Michihiro、Ishikawa Kyohei、Matsuno Genki、Kobayashi Akito、Miyagawa Kazuya、Tamura Masafumi、Berthier Claude、Kanoda Kazushi
    • Journal Title

      Science

      Volume: 358 Issue: 6369 Pages: 1403-1406

    • DOI

      10.1126/science.aan5351

    • Related Report
      2017 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Presentation] 強相関ディラック電子系a-(BEDT-TTF)2I3におけるNMR測定による圧力効果の研究 22019

    • Author(s)
      平田倫啓
    • Organizer
      日本物理学会第74回年次大会
    • Related Report
      2018 Annual Research Report
  • [Presentation] 有機導体のディラック電子系におけるフェルミ速度のくりこみ増大とエキシトニック不安定性のNMR研究2018

    • Author(s)
      平田倫啓
    • Organizer
      東北大金研強磁場コラボラトリ研究会
    • Related Report
      2018 Annual Research Report
  • [Presentation] 有機物のゼロ質量ディラックフェルミオン - 核磁気共鳴によるエキシトニックズピン揺らぎと多彩な強相関効果の観測2018

    • Author(s)
      平田倫啓
    • Organizer
      基研研究会「スピン系物理の最前線」
    • Related Report
      2018 Annual Research Report
  • [Presentation] Controlling excitonic instability of interacting 2D massless Dirac fermions in a layered organic salt2018

    • Author(s)
      Michihiro Hirata
    • Organizer
      Summit of Materials Science (SMS2018), IMR Tohoku University
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 強相関ディラック電子系a-(BEDT-TTF)2I3におけるNMR測定と理論計算による圧力効果の研究2018

    • Author(s)
      平田倫啓
    • Organizer
      日本物理学会2018年秋季大会
    • Related Report
      2018 Annual Research Report
  • [Presentation] 有機ディラック電子系a-(BEDT-TTF)2I3の強磁場下エキシトニック相2018

    • Author(s)
      小林晃人
    • Organizer
      日本物理学会2018年秋季大会
    • Related Report
      2018 Annual Research Report
  • [Presentation] Controlling Interactions and Probing Competition of Incipient Instabilities of Correlated 2D Weyl Fermions2018

    • Author(s)
      Michihiro Hirata
    • Organizer
      Conductivity and Magnetism in Molecular Materials - Gordon Research Conference
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Dirac cone reshaping, ferrimagnetic polarization and excitonic instability of 2D Weyl-Dirac fermions in a-(BEDT-TTF)2I32018

    • Author(s)
      Michihiro Hirata
    • Organizer
      Conductivity and Magnetism in Molecular Materials - Gordon Research Seminar
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Field and Pressure Controlled Dirac cone renormalization and excitonic instability of interacting 2D Weyl-Dirac fermions in a-(BEDT-TTF)2I3 probed via 13C NMR2018

    • Author(s)
      Michihiro Hirata
    • Organizer
      The 12th International Conference on Research in High Magnetic Fields
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 有機ディラック電子系における低温電子相関効果のNMR研究2018

    • Author(s)
      平田倫啓
    • Organizer
      日本物理学会第73回年次大会
    • Related Report
      2018 Annual Research Report
  • [Presentation] 有機ディラック電子系 a-(BEDT-TTF)2I3のエキシトニック相転移2018

    • Author(s)
      小林晃人
    • Organizer
      日本物理学会第73回年次大会
    • Related Report
      2018 Annual Research Report
  • [Presentation] 有機ディラック電子系における低温電子相関効果のNMR研究2018

    • Author(s)
      平田倫啓
    • Organizer
      日本物理学会
    • Related Report
      2017 Research-status Report
  • [Presentation] 有機ディラック電子系における面内磁場効果の強磁場NMR研究2017

    • Author(s)
      平田倫啓
    • Organizer
      日本物理学会
    • Related Report
      2017 Research-status Report
  • [Presentation] Extraordinary spin correlations and incipient excitonic instability of 2D Weyl fermions2017

    • Author(s)
      Michihiro Hirata
    • Organizer
      International Conference on Strongly Correlated Electron Systems (SCES2017)
    • Related Report
      2017 Research-status Report
    • Int'l Joint Research
  • [Presentation] Extraordinary spin correlations and incipient excitonic instability of 2D Weyl fermions2017

    • Author(s)
      Michihiro Hirata
    • Organizer
      International Conference on Topological Materials Science 2017 (TopoMat2017)
    • Related Report
      2017 Research-status Report
    • Int'l Joint Research
  • [Presentation] NMR evidence for anomalous spin correlations and excitonic instability of interacting Weyl fermions2017

    • Author(s)
      Michihiro Hirata
    • Organizer
      The 12th International Symposium on Crystalline Organic Metals, Superconductors and Magnets (ISCOM2017)
    • Related Report
      2017 Research-status Report
    • Int'l Joint Research
  • [Presentation] Anomalous Spin Correlations and Mass-Generating Excitonic Instability of Interacting Weyl Fermions2017

    • Author(s)
      Michihiro Hirata
    • Organizer
      New Frontier of Molecular Materials (NFMM) - ISCOM2017
    • Related Report
      2017 Research-status Report
    • Int'l Joint Research
  • [Presentation] 有機物質ディラック電子系における強相関効果の強磁場 NMR 研究2017

    • Author(s)
      平田倫啓
    • Organizer
      強磁場コラボラトリーが拓く未踏計測領域への挑戦と物質・材料科学の最先端
    • Related Report
      2017 Research-status Report
  • [Remarks] 東北大学金属材料研究所磁気物理学研究室ホームページ Publications

    • URL

      http://www.hfpm.imr.tohoku.ac.jp/html/research.html

    • Related Report
      2018 Annual Research Report
  • [Remarks] CNRS-LNCMI Publications

    • URL

      http://lncmi-g.grenoble.cnrs.fr/spip.php?rubrique128&lang=fr

    • Related Report
      2018 Annual Research Report
  • [Remarks] 東北大学金属材料研究所プレスリリース

    • URL

      http://www.imr.tohoku.ac.jp/ja/news/results/detail---id-961.html

    • Related Report
      2018 Annual Research Report

URL: 

Published: 2017-04-28   Modified: 2020-03-30  

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