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Theoretical study on the orbital and magnetic fluctuations on multi-orbital strongly-correlated electron systems

Research Project

Project/Area Number 17K14338
Research Category

Grant-in-Aid for Young Scientists (B)

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

Principal Investigator

Yamakawa Youichi  名古屋大学, 理学研究科, 講師 (60750312)

Project Period (FY) 2017-04-01 – 2021-03-31
Project Status Completed (Fiscal Year 2020)
Budget Amount *help
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2019: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2018: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2017: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
Keywords高温超伝導 / 強相関電子系 / 軌道秩序 / 磁気秩序 / 鉄系超伝導体 / 銅酸化物 / 超伝導 / ネマティック秩序 / ボンド秩序 / 軌道自由度 / 軌道揺らぎ / 磁気揺らぎ / 銅酸化物高温超伝導体 / 物性理論
Outline of Final Research Achievements

In this study, we investigated the electronic states in Fe-based and cuprate superconductors based on the higher-order many-body effect described by vertex corrections. As a result, we found that the orbital fluctuations are developed in electron-doped FeSe thanks to the interference between spin fluctuations. The high-temperature superconductivity appears due to the orbital fluctuations. Also, the pressure-induced magnetic transition in FeSe is well explained based on this study. We also showed that the resonance-like structure obtained by neutron scattering measurement is consistent with the s++ wave superconductivity due to orbital-fluctuations. In addition, we proposed the bond and spin-current orders as the origins of recently discovered charge-density wave and the pseud-gap nature in cuprate superconductors.

Academic Significance and Societal Importance of the Research Achievements

鉄系超伝導体をはじめとした多軌道強相関電子系では、電子の軌道・電荷・スピン自由度に起因して、様々な興味深い性質が現れる。本研究で明らかにしたバーテックス補正に起因した軌道揺らぎの発達とフルギャップs波超伝導発現の機構は、電子ドープFeSeの高温超伝導、ひいては鉄系全般の超伝導発現機構解明に貢献する結果である。また、銅酸化物高温超伝導体で新たに発見された電荷密度波、および擬ギャップ現象の起源として、バーテックス補正に起因したボンド・スピン流秩序という新機構を提唱した。鉄系および銅酸化物系超伝導体では、共にスピン・軌道・電荷の結合という共通の物理があり、強相関電子系において広く実現が期待される。

Report

(5 results)
  • 2020 Annual Research Report   Final Research Report ( PDF )
  • 2019 Research-status Report
  • 2018 Research-status Report
  • 2017 Research-status Report
  • Research Products

    (35 results)

All 2021 2020 2019 2018 2017

All Journal Article (14 results) (of which Int'l Joint Research: 1 results,  Peer Reviewed: 14 results) Presentation (21 results) (of which Int'l Joint Research: 2 results,  Invited: 6 results)

  • [Journal Article] Doping effects on electronic states in electron-doped FeSe: Impact of self-energy and vertex corrections2020

    • Author(s)
      Yamakawa Youichi、Onari Seiichiro、Kontani Hiroshi
    • Journal Title

      Physical Review B

      Volume: 102 Issue: 8 Pages: 081108-081108

    • DOI

      10.1103/physrevb.102.081108

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed
  • [Journal Article] 汎関数くりこみ群法による教相関電子系の研究 ー2次元電子系におけるネマティック秩序ー2020

    • Author(s)
      土射津昌久, 田財里奈, 山川洋一, 紺谷浩
    • Journal Title

      固体物理

      Volume: 55 Pages: 195-203

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Pressure-induced quantum critical point in the heavily hydrogen-doped iron-based superconductor LaFeAsO2019

    • Author(s)
      Takeuchi Masayoshi、Fujiwara Naoki、Kuwayama Takanori、Nakagawa Satoshi、Iimura Soshi、Matsuishi Satoru、Yamakawa Youichi、Kontani Hiroshi、Hosono Hideo
    • Journal Title

      Physical Review B

      Volume: 99 Issue: 17 Pages: 174517-174517

    • DOI

      10.1103/physrevb.99.174517

    • NAID

      120006636656

    • Related Report
      2019 Research-status Report
    • Peer Reviewed
  • [Journal Article] Superconductivity in PtSbS with a Noncentrosymmetric Cubic Crystal Structure2019

    • Author(s)
      Ryosuke Mizutani, Yoshihiko Okamoto, Hayate Nagaso, Youichi Yamakawa, Hiroshi Takatsu, Hiroshi Kageyama, Shunichiro Kittaka, Yohei Kono, Toshiro Sakakibara, and Koshi Takenaka
    • Journal Title

      Journal of the Physical Society of Japan

      Volume: 88 Issue: 9 Pages: 093709-093709

    • DOI

      10.7566/jpsj.88.093709

    • NAID

      40022008736

    • Related Report
      2019 Research-status Report
    • Peer Reviewed
  • [Journal Article] Self-energy driven resonancelike inelastic neutron spectrum in the s++-wave state in Fe-based superconductors2018

    • Author(s)
      L. Takeuchi, Y. Yamakawa, and H. Kontani
    • Journal Title

      Physical Review B

      Volume: 98 Issue: 16 Pages: 1-11

    • DOI

      10.1103/physrevb.98.165143

    • Related Report
      2018 Research-status Report
    • Peer Reviewed
  • [Journal Article] Pairing mechanism for nodal s-wave superconductivity in BaFe2(As,P)2: Analysis beyond Migdal-Eliashberg formalism2018

    • Author(s)
      H. Nakaoka, Y. Yamakawa, and H. Kontani
    • Journal Title

      Physical Review B

      Volume: 98 Issue: 12 Pages: 1-12

    • DOI

      10.1103/physrevb.98.125107

    • Related Report
      2018 Research-status Report
    • Peer Reviewed
  • [Journal Article] Edge-induced Strongly Correlated Electronic States in Two-dimensional Hubbard Model: Enhancement of Magnetic Correlations and Self-energy Effects2018

    • Author(s)
      S. Matsubara, Y. Yamakawa, and H. Kontani
    • Journal Title

      Journal of the Physical Society of Japan

      Volume: 87 Issue: 7 Pages: 073705-073705

    • DOI

      10.7566/jpsj.87.073705

    • NAID

      210000134884

    • Related Report
      2018 Research-status Report
    • Peer Reviewed
  • [Journal Article] Multistage electronic nematic transitions in cuprate superconductors: A functional-renormalization-group analysis2018

    • Author(s)
      M. Tsuchiizu, K. Kawaguchi, Y. Yamakawa, and H. Kontani
    • Journal Title

      Phys. Rev. B

      Volume: 97 Issue: 16 Pages: 165131-165131

    • DOI

      10.1103/physrevb.97.165131

    • Related Report
      2018 Research-status Report
    • Peer Reviewed
  • [Journal Article] Large thermoelectric power factor in one-dimensional telluride Nb4SiTe4 and substituted compounds2018

    • Author(s)
      Y. Okamoto, T. Wada, Y. Yamakawa, T. Inohara, and K. Takenaka
    • Journal Title

      Applied Physics Letters

      Volume: 112 Issue: 17

    • DOI

      10.1063/1.5023427

    • Related Report
      2018 Research-status Report
    • Peer Reviewed
  • [Journal Article] Abrupt change of the superconducting gap structure at the nematic critical point in FeSe1?xSx2018

    • Author(s)
      Sato Yuki、Kasahara Shigeru、Taniguchi Tomoya、Xing Xiangzhuo、Kasahara Yuichi、Tokiwa Yoshifumi、Yamakawa Youichi、Kontani Hiroshi、Shibauchi Takasada、Matsuda Yuji
    • Journal Title

      Proceedings of the National Academy of Sciences

      Volume: 115 Issue: 6 Pages: 1227-1231

    • DOI

      10.1073/pnas.1717331115

    • Related Report
      2017 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Competing Unconventional Charge-Density-Wave States in Cuprate Superconductors: Spin-Fluctuation-Driven Mechanism2017

    • Author(s)
      K. Kawaguchi, Y. Yamakawa, M. Tsuchiizu, and H. Kontani
    • Journal Title

      J. Phys. Soc. Jpn.

      Volume: 86 Issue: 6 Pages: 063707-063707

    • DOI

      10.7566/jpsj.86.063707

    • NAID

      40021221661

    • Related Report
      2017 Research-status Report
    • Peer Reviewed
  • [Journal Article] Plain s-Wave Superconductivity near Magnetic Criticality: Enhancement of Attractive Electron-Boson Coupling Vertex Corrections2017

    • Author(s)
      R. Tazai, Y. Yamakawa, M. Tsuchiizu, and H. Kontani
    • Journal Title

      J. Phys. Soc. Jpn.

      Volume: 86 Issue: 7 Pages: 073703-073703

    • DOI

      10.7566/jpsj.86.073703

    • NAID

      40021254022

    • Related Report
      2017 Research-status Report
    • Peer Reviewed
  • [Journal Article] Superconductivity without a hole pocket in electron-doped FeSe: Analysis beyond the Migdal-Eliashberg formalism2017

    • Author(s)
      Yamakawa Youichi、Kontani Hiroshi
    • Journal Title

      Physical Review B

      Volume: 96 Issue: 4

    • DOI

      10.1103/physrevb.96.045130

    • Related Report
      2017 Research-status Report
    • Peer Reviewed
  • [Journal Article] Nematicity, magnetism, and superconductivity in FeSe under pressure: Unified explanation based on the self-consistent vertex correction theory2017

    • Author(s)
      Yamakawa Youichi、Kontani Hiroshi
    • Journal Title

      Physical Review B

      Volume: 96 Issue: 14

    • DOI

      10.1103/physrevb.96.144509

    • Related Report
      2017 Research-status Report
    • Peer Reviewed
  • [Presentation] Unconventional orbital-charge density wave mechanism in transition metal dichalcogenide 1T-TaS22021

    • Author(s)
      Toru, Hirata, Youichi Yamakawa, Seiichiro Onari, Hiroshi Kontani
    • Organizer
      APS March Meeting 2021, online, March-2021
    • Related Report
      2020 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Unconventional orbital-charge density wave mechanism in transition metal dichalcogenide 1T-TaS22020

    • Author(s)
      山川洋一、平田徹、大成誠一郎、紺谷浩
    • Organizer
      令和2年度 新学術領域研究「量子液晶の物性科学」領域研究会
    • Related Report
      2020 Annual Research Report
  • [Presentation] 遷移金属ダイカルコゲナイドにおける非従来型電荷秩序の微視的理論2020

    • Author(s)
      山川洋一、平田徹、大成誠一郎、紺谷浩
    • Organizer
      新学術領域研究「量子液晶の物性科学」量子物質開発フォーラム
    • Related Report
      2020 Annual Research Report
  • [Presentation] 拡張軌道揺らぎ由来の超伝導の理論研究:高ドープFeSeへの適用2020

    • Author(s)
      山川洋一, 大成誠一郎, 紺谷浩
    • Organizer
      日本物理学会 2020年秋季大会
    • Related Report
      2020 Annual Research Report
  • [Presentation] FeSe系における軌道・磁気揺らぎと超伝導の理論研究2020

    • Author(s)
      山川洋一, 大成誠一郎, 紺谷浩
    • Organizer
      日本物理学会 第75回年次大会
    • Related Report
      2019 Research-status Report
  • [Presentation] Development of orbital fluctuations and s-wave superconductivity due to AL-VC in electron-doped FeSe2019

    • Author(s)
      Y. Yamakawa, S. Onari, H. Kontani
    • Organizer
      Spectroscopies in Novel Superconductors 2019
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research
  • [Presentation] 銅酸化物超伝導体におけるボンド秩序の圧力および磁場依存性2019

    • Author(s)
      山川洋一
    • Organizer
      高温超伝導フォーラム第7回会合
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] ハバード模型における非自明な電荷秩序相の理論研究2019

    • Author(s)
      山川洋一, 大成誠一郎, 紺谷浩
    • Organizer
      日本物理学会 2019年秋季大会
    • Related Report
      2019 Research-status Report
  • [Presentation] 電子ドープFeSeにおける高温超伝導および銅酸化物の圧力・磁場下でのボンド秩序の理論研究2019

    • Author(s)
      山川洋一、大成誠一郎、紺谷浩
    • Organizer
      京都大学基礎物理学研究所研究会「電子相関が生み出す超伝導現象の未解決問題と新しい潮流」
    • Related Report
      2019 Research-status Report
  • [Presentation] FeSe系における軌道・磁気揺らぎと超伝導の理論研究2019

    • Author(s)
      山川洋一
    • Organizer
      第9回「凝縮系理論の最前線」
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] FeSe系超伝導体における電子ドープ効果の理論研究2019

    • Author(s)
      山川洋一, 大成誠一郎, 紺谷浩
    • Organizer
      日本物理学会 第74回年次大会
    • Related Report
      2018 Research-status Report
  • [Presentation] 鉄系超伝導体におけるドーピング効果2018

    • Author(s)
      山川洋一
    • Organizer
      第八回「強相関電子系理論の最前線」
    • Related Report
      2018 Research-status Report
    • Invited
  • [Presentation] 電子ドープFeSeにおける超伝導発現機構の理論研究2018

    • Author(s)
      山川洋一
    • Organizer
      日本物理学会北陸支部特別講演会
    • Related Report
      2018 Research-status Report
    • Invited
  • [Presentation] 鉄系超伝導体における四重極揺らぎと超伝導の理論研究2018

    • Author(s)
      山川洋一, 紺谷浩
    • Organizer
      J-Physics:多極子伝導系の物理 平成 30 年度領域全体会議
    • Related Report
      2018 Research-status Report
  • [Presentation] FeSe系の超伝導における軌道・スピン・電荷揺らぎの効果2018

    • Author(s)
      山川洋一, 紺谷浩, 大成誠一郎
    • Organizer
      基研研究会「電子相関が生み出す新規な秩序と超伝導現象」
    • Related Report
      2018 Research-status Report
    • Invited
  • [Presentation] Multistage CDW Transitions in Cuprate High-Tc Superconductors: Functional-Renormalization-Group Analysis2018

    • Author(s)
      Hiroshi Kontani, Masahisa Tsuchiizu, Kouki Kawaguchi, Youichi Yamakawa
    • Organizer
      APS March Meeting 2018
    • Related Report
      2017 Research-status Report
  • [Presentation] Nematicity and superconductivity in FeSe1-xSx2018

    • Author(s)
      Youichi Yamakawa, Hiroshi Kontani
    • Organizer
      APS March Meeting 2018
    • Related Report
      2017 Research-status Report
  • [Presentation] 鉄系超伝導体における超伝導と軌道・磁気複合揺らぎの協奏2017

    • Author(s)
      山川洋一
    • Organizer
      基研研究会「超伝導研究の最先端:多自由度、非平衡、電子相関、トポロジー、人工制御」
    • Related Report
      2017 Research-status Report
    • Invited
  • [Presentation] FeSe系におけるS++波超伝導発現機構:電子相関効果と電子格子相互作用の協力機構2017

    • Author(s)
      山川洋一, 紺谷浩
    • Organizer
      日本物理学会 2017年秋季大会
    • Related Report
      2017 Research-status Report
  • [Presentation] FeSe1-xSxにおけるネマティシティと超伝導の理論研究:軌道とスピンの協力機構2017

    • Author(s)
      山川洋一, 紺谷浩
    • Organizer
      超伝導フォーラム第5回会合
    • Related Report
      2017 Research-status Report
  • [Presentation] 多体相関に起因した軌道・電荷・スピン揺らぎと超伝導2017

    • Author(s)
      山川洋一
    • Organizer
      第七回「強相関電子系理論の最前線」
    • Related Report
      2017 Research-status Report

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Published: 2017-04-28   Modified: 2022-01-27  

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