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Study on Electron Pair Formation in Molecular Superconductors with Orbital Degrees of Freedom

Research Project

Project/Area Number 19K05405
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Review Section Basic Section 32020:Functional solid state chemistry-related
Research InstitutionEhime University

Principal Investigator

Takashi Yamamoto  愛媛大学, 理工学研究科(理学系), 准教授 (20511017)

Project Period (FY) 2019-04-01 – 2024-03-31
Project Status Completed (Fiscal Year 2023)
Budget Amount *help
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2022: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2021: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2020: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Keywords軌道自由度 / 分子性固体 / 超伝導体 / 金属-絶縁体転移 / 反強磁性 / 近赤外分光法 / 振動分光法 / 四次元X線回折 / 分子性導体 / 分子軌道自由度 / 分子分光 / 金属ジチオレン錯体 / 分子性伝導体 / 高圧 / 分子性超伝導体 / 一軸圧縮
Outline of Research at the Start

超伝導には、永久電流を担うための弱い電子対を形成する結合力が必要である。一方で、電子を引き離す反発力による磁気的効果も無視できない。本研究では、分子性超伝導体を用いて、結合力と反発力が両立できる「からくり」を解明する。分子性結晶の超伝導体は、HOMOとLUMOの準位が近いので、軌道自由度が存在する。例えば「HOMOは結合力を担い、LUMOは反発力を担う」というように、互いの役割が独立している。分光学的手法による結合力と反発力の定量化を行うことで、弱い電子対の形成に適した条件を見出す。また、結合力や反発力を選択的に促進させることで、分子性結晶に複合的機能を付与できるのか試みる。

Outline of Final Research Achievements

Molecular conductors and magnets are useful model compounds in solid state physics. In this study, we investigated whether superconductors and other compounds with close orbital levels are also useful as model compounds. We were able to determine the occupied (unoccupied) orbitals and their levels by spectroscopic methods for metal-dithiolene complex salts with close HOMO and LUMO levels. In the metal-insulator phase transition of three platinum complex salts, an orbital degree-of-freedom-based phase transition was found in which the orbital levels of half of the molecules are swapped. In the palladium complex salt, a superconductor under pressure, a ground state with a partial Valence Bond Order was found due to instability of the outermost orbital. The orbital instability was also detected by X-ray diffraction.

Academic Significance and Societal Importance of the Research Achievements

本研究成果により、近接した準位の軌道による効果が物性に影響を及ぼすと考えられている系の電子状態を探る本格的な実験的研究が可能になる。例えば、単一成分の分子性超伝導体における電子対の探索や、分子性のディラック電子系において光速に近いキャリアの源を探る研究などに着手できるようになる。無機物のd軌道とは異なり、HOMOとLUMOという二準位のみから成る単純な電子系を用いることで、磁性と伝導性や光学特性を絡めた新奇現象を探索することが可能になる。

Report

(6 results)
  • 2023 Annual Research Report   Final Research Report ( PDF )
  • 2022 Research-status Report
  • 2021 Research-status Report
  • 2020 Research-status Report
  • 2019 Research-status Report
  • Research Products

    (21 results)

All 2024 2023 2022 2021 2020 2019 Other

All Int'l Joint Research (2 results) Journal Article (8 results) (of which Int'l Joint Research: 1 results,  Peer Reviewed: 8 results,  Open Access: 1 results) Presentation (11 results) (of which Int'l Joint Research: 2 results,  Invited: 2 results)

  • [Int'l Joint Research] Universite de Rennes(フランス)

    • Related Report
      2023 Annual Research Report
  • [Int'l Joint Research] Nottingham Trent University(英国)

    • Related Report
      2023 Annual Research Report
  • [Journal Article] Frustrated competitive forces in the Et2Me2Sb[Pd(dmit)2]2 molecular conductor2023

    • Author(s)
      Guerin Laurent、Trzop Elzbieta、Ishikawa Tadahiko、Koshihara Shinya、Yamamoto Takashi、Toudic Bertrand、Kato Reizo
    • Journal Title

      Physical Review B

      Volume: 108 Issue: 13 Pages: 134104-134104

    • DOI

      10.1103/physrevb.108.134104

    • Related Report
      2023 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Orbital Degree of Freedom in Conducting Platinum-Dithiolene Complex Salts2023

    • Author(s)
      Yamamoto Takashi、Hiraga Daiki、Arashi Ikumi、Takasugi Koh、Naito Toshio、Ishikawa Tadahiko、Okimoto Yoichi、Koshihara Shin-ya、Nomura Mitsushiro、Kato Reizo
    • Journal Title

      Journal of the Physical Society of Japan

      Volume: 92 Issue: 2 Pages: 24701-24701

    • DOI

      10.7566/jpsj.92.024701

    • Related Report
      2022 Research-status Report
    • Peer Reviewed
  • [Journal Article] Enhancements of Superconductivity and Insulating Electrical Resistivity under the Same Uniaxial Strain in a Molecular Conductor2022

    • Author(s)
      Yuichi Okii, Takashi Yamamoto, Toshio Naito, Kensuke Konishi, Hiroki Akutsu, and Yasuhiro Nakazawa
    • Journal Title

      J. Phys. Soc. Jpn.

      Volume: 91 Issue: 3

    • DOI

      10.7566/jpsj.91.034707

    • NAID

      210000188948

    • Related Report
      2021 Research-status Report
    • Peer Reviewed
  • [Journal Article] Organic charge transfer complex at the boundary between superconductors and insulators: critical role of a marginal part of the conduction pathways2022

    • Author(s)
      Toshio Naito, Hayato Takeda, Yusuke Matsuzawa, Megumi Kurihara, Akio Yamada, Yusuke Nakamura and Takashi Yamamoto
    • Journal Title

      Materials Advances

      Volume: 3 Issue: 3 Pages: 1506-1511

    • DOI

      10.1039/d1ma00933h

    • Related Report
      2021 Research-status Report
    • Peer Reviewed
  • [Journal Article] Lattice and Charge Fluctuations in a Molecular Superconductors2021

    • Author(s)
      T. Yamamoto, T. Naito, M. Uruichi, H. Akutsu, and Y. Nakazawa
    • Journal Title

      J. Phys. Soc. Jpn.

      Volume: 90 Issue: 6 Pages: 0637081-5

    • DOI

      10.7566/jpsj.90.063708

    • NAID

      40022591115

    • Related Report
      2021 Research-status Report
    • Peer Reviewed
  • [Journal Article] Coexistence of Interchanged and Normal Orbital Levels in a Molecular Conductor Consisting of a Metal-Dithiolene Complex2021

    • Author(s)
      Takashi Yamamoto, Daiki Hiraga, Ikumi Arashi, Koh Takasugi, Toshio Naito, Mikio Uruichi, Fumitsuna Teshima, Kiyohisa Tanaka, Mitsushiro Nomura, and Reizo Kato
    • Journal Title

      J. Phys. Soc. Jpn.

      Volume: 90 Issue: 11

    • DOI

      10.7566/jpsj.90.114704

    • NAID

      40022739030

    • Related Report
      2021 Research-status Report
    • Peer Reviewed
  • [Journal Article] Electronic Inhomogeneity in Organic Charge Transfer Salt κ-(BEDT-TTF)2Cu[N(CN)2]I Probed by Polarized Femtosecond Spectroscopy2020

    • Author(s)
      Tsuchiya Satoshi、Kuwae Ryota、Kodama Takumi、Nakamura Yusuke、Kurihara Megumi、Yamamoto Takashi、Naito Toshio、Toda Yasunori
    • Journal Title

      Journal of the Physical Society of Japan

      Volume: 89 Issue: 6 Pages: 064712-064712

    • DOI

      10.7566/jpsj.89.064712

    • NAID

      40022254224

    • Related Report
      2020 Research-status Report 2019 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] Electrical Resistivity under Uniaxial Pressures of β′′-(bis-ethelenedithio-tetrathiafulvalene)4Pd(CN)4H2O2020

    • Author(s)
      Okii Yuichi、Yamamoto Takashi、Konishi Kensuke、Naito Toshio
    • Journal Title

      Journal of the Physical Society of Japan

      Volume: 89 Issue: 3 Pages: 034709-034709

    • DOI

      10.7566/jpsj.89.034709

    • NAID

      210000158043

    • Related Report
      2019 Research-status Report
    • Peer Reviewed
  • [Presentation] 新規カッパー型ET塩における電子不均一相2024

    • Author(s)
      山本貴、L. Martin, 売市幹夫
    • Organizer
      日本物理学会 2024年 春季大会
    • Related Report
      2023 Annual Research Report
  • [Presentation] Inhomogeneity of Intermolecular Interaction in Molecule-Based Superconductor2023

    • Author(s)
      T. Yamamoto
    • Organizer
      Workshop of Thermal and Entropic Science - Interplay of Condensed Matter Chemistry and Physics -
    • Related Report
      2023 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] κ-(BEST)2Cu2(CN)3に観測される線幅の広いラマンピークの解析2023

    • Author(s)
      山本 貴、売市幹夫、小林 拓矢、谷口弘三、齋藤 陸丸、河本 充司
    • Organizer
      日本物理学会 第78回 年次大会
    • Related Report
      2023 Annual Research Report
  • [Presentation] NPDおよびType-IIaダイヤと液体媒体で加圧した分子結晶の赤外偏光反射スペクトル2022

    • Author(s)
      山本貴*、立花侑果、内藤俊雄、新名亨、入舩撤男
    • Organizer
      第63回高圧討論会
    • Related Report
      2022 Research-status Report
  • [Presentation] 伝導性分子結晶における軌道自由度2022

    • Author(s)
      山本貴*
    • Organizer
      日本化学会中国四国支部大会
    • Related Report
      2022 Research-status Report
    • Invited
  • [Presentation] Unidirectional Tetramer Formed in Molecule-Based Superconductor2022

    • Author(s)
      Takashi Yamamoto,* Yuichi Okii, Toshio Naito, Kensuke Konishi, Mikio Uruichi, Hiroki Akutsu, Yasuhiro Nakazawa
    • Organizer
      The 14th International Symposium on Crystalline Organic Metals, Superconductors and Magnets (ISCOM2022)
    • Related Report
      2022 Research-status Report
    • Int'l Joint Research
  • [Presentation] 液体圧力媒体を使った伝導性分子結晶の赤外反射スペクトル2021

    • Author(s)
      立花侑果, 山本貴, 内藤俊雄
    • Organizer
      第62回高圧討論会
    • Related Report
      2021 Research-status Report
  • [Presentation] 超伝導状態で四量体化揺らぎと電荷揺らぎを示すベータダブルプライム塩2021

    • Author(s)
      山本貴,内藤俊雄,売市幹大,圷広樹,中澤康浩
    • Organizer
      日本物理学会2021年秋季大会
    • Related Report
      2021 Research-status Report
  • [Presentation] 白金ジチオレン錯体塩の 電子スペクトル2020

    • Author(s)
      山本貴, 内藤俊雄, 石川忠彦, 沖本洋一, 腰原伸也, 加藤礼三
    • Organizer
      日本物理学会第76回年次大会
    • Related Report
      2020 Research-status Report
  • [Presentation] 非ダイマーモット型の有機超伝導体 における 一軸圧縮効果2019

    • Author(s)
      山本 貴, 沖井 優一, 東澤 玲央, 内藤 俊雄, 圷 広樹, 中澤 康浩
    • Organizer
      高圧討論会
    • Related Report
      2019 Research-status Report
  • [Presentation] 時間分解分光による k-(BEDT-TTF)2Cu[N(CN)2]Iにおける不均一な電子状態の観測2019

    • Author(s)
      土屋聡、 桑江良太、児玉匠、戸田泰則、中村祐介、栗原芽来美、山本貴、内藤俊雄
    • Organizer
      日本物理学会2019年秋季大会
    • Related Report
      2019 Research-status Report

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Published: 2019-04-18   Modified: 2025-01-30  

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