Exploration of novel superconducting states in transition metal compounds with a honeycomb structure

• Project/Area Number: 19K03748
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: Osaka University (2020-2021); Okayama University (2019)
• Principal Investigator: Kazutaka Kudo 大阪大学, 理学研究科, 教授 (40361175)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2021: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2020: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
• Keywords: 新奇超伝導状態 / ハニカムネットワーク / カイラル超伝導 / カゴメネットワーク / 超伝導材料

Outline of Research at the Start

本研究では、研究代表者が発見した新超伝導体BaPtSb、SrPtAs、β-BaPtAs、γ-BaPtAsにおいて、カイラルd波超伝導状態の探索と新奇物性の開拓を行う。これらの超伝導体はハニカム構造を持つ。本研究の独創性は、構造の対称性からカイラルd波超伝導状態が自然に導かれるハニカム構造に着目した点にある。研究方法は、良質な単結晶試料の育成、磁化・電気抵抗・比熱による超伝導基礎物性の測定、ミュオンスピン回転／緩和法によるカイラルd波超伝導状態の実証や表面スピン流検出の試みからなる。

Outline of Final Research Achievements

In the superconducting state of compounds with a honeycomb network, we observed an increase in the muon spin relaxation rate that suggests a spontaneous magnetic field. The increase disappeared with impurity doping. These cannot be explained by conventional superconducting states. In honeycomb networks, the emergence of exotic superconducting states has been predicted based on the symmetry. Detailed consideration on superconducting electron pairs is currently underway along with the in-depth analysis. Furthermore, we explored superconductors with Kagome and triangular networks, which are expected to exhibit exotic superconductivity as well as honeycomb networks based on their symmetry, and discovered several new superconductors.

Academic Significance and Societal Importance of the Research Achievements

原子ネットワークの対称性に着目して系統的に超伝導物質開発を行い、新奇超伝導状態を探索したことに本研究の意義がある。当初から着目していたハニカムネットワークだけでなく、三角形ネットワーク、カゴメネットワークへと研究対象が広がり、より普遍的な知見を得るための研究へと発展させる準備が整った。

Research Products

• [Int'l Joint Research] Paul Scherrer Institut (PSI)(スイス)
• [Int'l Joint Research] The Paul Scherrer Institute(スイス)
• [Int'l Joint Research] Universita di Roma “La Sapienza”(イタリア)
• [Int'l Joint Research] Paul Scherrer Institut(スイス)
• [Journal Article] Enhanced Superconductivity in Close Proximity to Polar-Nonpolar Structural Phase Transition in Se/Te-Substituted PtBi2 (2022)
  • Author(s): K. Takaki, M. Yamamoto, M. Nakajima, T. Takeuchi, H. Y. Nguyen, M. Nohara, Y. Kishioji, T. Fujii, K. Yoshino, S. Miyasaka, and K. Kudo
  • Journal Title: Journal of the Physical Society of Japan Volume: 91 Issue: 3
  • DOI: 10.7566/jpsj.91.034703
  • NAID: 210000188846
  • Peer Reviewed
• [Journal Article] Superconductivity of the Stuffed CdI2-type Pt1+xBi2 (2021)
  • Author(s): K. Kudo, H. Y. Nguyen, C.-g. Oh, K. Takaki, and M. Nohara
  • Journal Title: Journal of the Physical Society of Japan Volume: 90 Issue: 6 Pages: 063706-063706
  • DOI: 10.7566/jpsj.90.063706
  • NAID: 40022591105
  • Peer Reviewed
• [Journal Article] Pressure Induced Spectral Redistribution due to Te2 Dimer Breaking in AuTe2 (2021)
  • Author(s): D. Ootsuki, H. Okamura, S. Mitsumoto, Y. Ikemoto, T. Moriwaki, M. Arita, T. Yoshida, K. Kudo, H. Ishii, M. Nohara, and T. Mizokawa
  • Journal Title: Journal of the Physical Society of Japan Volume: 90 Issue: 11
  • DOI: 10.7566/jpsj.90.114705
  • NAID: 210000159424
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Superconductivity of the Partially Ordered Laves Phase Mg2Ir2.3Ge1.7 (2020)
  • Author(s): K. Kudo, T. Honda, H. Hiiragi, H. Ota, and M. Nohara
  • Journal Title: Journal of the Physical Society of Japan Volume: 89 Issue: 12 Pages: 123701-123701
  • DOI: 10.7566/jpsj.89.123701
  • NAID: 40022436752
  • Peer Reviewed
• [Journal Article] Superconductivity in Mg2Ir3Si: A Fully Ordered Laves Phase (2020)
  • Author(s): K. Kudo, H. Hiiragi, T. Honda, K. Fujimura, H. Idei, M. Nohara
  • Journal Title: Journal of the Physical Society of Japan Volume: 89 Issue: 1 Pages: 013701-013701
  • DOI: 10.7566/jpsj.89.013701
  • NAID: 210000157736
  • Peer Reviewed
• [Journal Article] Impact of Local Atomic Fluctuations on Superconductivity of Pr-Substituted CaFe2As2 Studied by X-ray Fluorescence Holography (2019)
  • Author(s): K. Kudo, S. Ioka, N. Happo, H. Ota, Y. Ebisu, K. Kimura, T. Hada, T. Kimura, H. Tajiri, S. Hosokawa, K. Hayashi, M. Nohara
  • Journal Title: Journal of the Physical Society of Japan Volume: 88 Issue: 6 Pages: 063704-063704
  • DOI: 10.7566/jpsj.88.063704
  • NAID: 40021915136
  • Peer Reviewed / Open Access
• [Journal Article] Interplay between spin-orbit interaction and stripe-type charge-orbital order of IrTe2 (2019)
  • Author(s): D. Ootsuki, H. Ishii, K. Kudo, M. Nohara, M. Arita, H. Namatame, M. Taniguchi, N. L. Saini, T. Mizokawa
  • Journal Title: Journal of Physics and Chemistry of Solids Volume: 128 Pages: 270-274
  • DOI: 10.1016/j.jpcs.2018.02.015
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] The local structure of the Ca0.9Pr0.1Fe2As2 superconductor as a function of temperature (2019)
  • Author(s): E. Paris, T. Wakita, L. Simonelli, C. Marini, W. Olszewski, K. Terashima, F. Stramaglia, G. M. Pugliese, T. Mizokawa, S. Ioka, K. Kudo, M. Nohara, T. Yokoya, N. L. Saini
  • Journal Title: Superconductor Science and Technology Volume: 32 Issue: 9 Pages: 095001-095001
  • DOI: 10.1088/1361-6668/ab2792
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Thermal Conductivity and Magnetic Phase Diagram of CuB2O4 (2019)
  • Author(s): Takayuki Kawamata, Naoki Sugawara, Siyed Mohammad Haidar, Tadashi Adachi, Takashi Noji, Kazutaka Kudo, Norio Kobayashi, Yutaka Fujii, Hikomitsu Kikuchi, Meiro Chiba, German A. Petrakovskii, Mikhail A. Popov, Leonard N. Bezmaternykh, Yoji Koike
  • Journal Title: Journal of the Physical Society of Japan Volume: 88 Issue: 11 Pages: 114708-114708
  • DOI: 10.7566/jpsj.88.114708
  • NAID: 40022062720
  • Peer Reviewed / Int'l Joint Research
• [Presentation] 三角形・ハニカム・カゴメネットワークを持つ超伝導体の物質開発 (2022)
  • Author(s): 工藤一貴
  • Organizer: 日本中間子科学会研究会「ミュオンで見る磁性・超伝導物質研究の最前線」
  • Invited
• [Presentation] Superconductivity in Pt1+xBi2 with a stuffed CdI2-type structure (2022)
  • Author(s): 工藤一貴
  • Organizer: 令和 3 年度 新学術領域研究「量子液晶の物性科学」領域研究会
• [Presentation] ハニカムネットワークを持つBaPt(As1-xSbx)の合成と超伝導特性 (2022)
  • Author(s): 小川泰輝、竹内徹也、木田孝則、萩原政幸、工藤一貴
  • Organizer: 日本物理学会第77回年次大会
• [Presentation] Ba(Fe1-xCrx)2As2 における電荷ネマティックラマン応答のCr置換量依存性 (2022)
  • Author(s): 片山和郷、足立徹、小林達也、中島正道、宮坂茂樹、工藤一貴
  • Organizer: 日本物理学会第77回年次大会
• [Presentation] 化学ドープした PtBi2 における超伝導転移温度の上昇 (2022)
  • Author(s): 高木健輔、竹内徹也、中島正道、工藤一貴
  • Organizer: 日本物理学会第77回年次大会
• [Presentation] SeドープPtBi2薄膜の超伝導特性 (2022)
  • Author(s): 前田将輝、徳田将志、中村瞭弥、高木健輔、工藤一貴、新見康洋
  • Organizer: 日本物理学会第77回年次大会
• [Presentation] Superconductivity of the Fully and Partially Ordered Laves Phase Compounds (2021)
  • Author(s): K. Kudo, T. Honda, H. Hiiragi, and M. Nohara
  • Organizer: International Conference on Quantum Liquid Crystals 2021 (QLC2021)
  • Int'l Joint Research
• [Presentation] Chiral Superconductivity in BaPtAs1-x Sbx with a Honeycomb Network (2021)
  • Author(s): T. Adachi, K. Kudo, Y. Saito, T. Sumura, K. Kawabata, T. Takeuchi, A. Koda, H. Okabe, R. Kadono, T. U. Ito, W. Higemoto, C. Baines, I. Watanabe, and M. Nohara
  • Organizer: International Conference on Quantum Liquid Crystals 2021 (QLC2021)
  • Int'l Joint Research
• [Presentation] 秩序型ラーベス相構造を利用した超伝導体の開発 (2021)
  • Author(s): 工藤一貴
  • Organizer: 令和 3 年度「第 2 回 強磁場コラボラトリー オンラインセミナー」
  • Invited
• [Presentation] 秩序型ラーベス相化合物の超伝導物質開発 (2021)
  • Author(s): 工藤一貴
  • Organizer: 第5回固体化学フォーラム研究会
  • Invited
• [Presentation] インターグロース構造を利用した層状ペロブスカイト型 V 酸化物の相転移現象の研究 (2021)
  • Author(s): 藤井隆弘、中島正道、工藤一貴
  • Organizer: 日本物理学会2021年秋季大会
• [Presentation] ハニカム構造を持つBaPt(As1-xSbx)の超伝導 (2021)
  • Author(s): 小川泰輝、竹内貴亮、齋藤有紀、竹内徹也、宮坂茂樹、中島正道、野原実、工藤一貴
  • Organizer: 日本物理学会2021年秋季大会
• [Presentation] CdI2型Pt(Bi1-xChx)2 (Ch = Se, Te) の超伝導 (2021)
  • Author(s): 高木健輔、山本真由、中島正道、竹内徹也、Hoang Yen Nguyen、野原実、宮坂茂樹、工藤一貴
  • Organizer: 日本物理学会2021年秋季大会
• [Presentation] 秩序型ラーベス相化合物における新規超伝導体の開発（シンポジウム講演） (2020)
  • Author(s): 工藤一貴
  • Organizer: 日本物理学会2020年秋季大会
  • Invited
• [Presentation] Development of New Superconductors with Ordered Laves Phase Structures (2020)
  • Author(s): K. Kudo
  • Organizer: The 33rd International Symposium on Superconductivity (ISS2020)
  • Int'l Joint Research / Invited
• [Presentation] Development of Superconductors with Ordered Laves Phase Structures (2020)
  • Author(s): K. Kudo, T. Honda, H. Hiiragi, H. Ota, and M. Nohara
  • 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
• [Presentation] Possible Chiral d-Wave Superconductivity in BaPtAs1-xSbx with the Honeycomb Network (2020)
  • Author(s): T. Adachi, K. Kudo, Y. Saito, T. Sumura, K. Kawabata, T. Takeuchi, A. Koda, H. Okabe, R. Kadono, T. U. Ito, W. Higemoto, C. Baines, I. Watanabe, and M. Nohara
  • 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
• [Presentation] 秩序型ラーベス相Mg2Ir3SiとLi2IrSi3の超伝導 (2020)
  • Author(s): 工藤一貴, 柊輝, 本田寿明, 野原実
  • Organizer: J-Physics：多極子伝導系の物理 令和元年度領域全体会議
• [Presentation] 秩序型ラーベス相Mg2Ir3Siの超伝導 (2020)
  • Author(s): 工藤一貴, 柊輝, 本田寿明, 藤村一徳, 出井宏幸, 野原実,
  • Organizer: 日本物理学会第75回年次大会
• [Presentation] Development of novel hexagonal superconductors with 5d transition metals (2019)
  • Author(s): K. Kudo
  • Organizer: Progress in Superconductivity Research - RIIS Mini-Workshop -
  • Int'l Joint Research / Invited
• [Presentation] Exploration of Novel Pt-Based Superconductors with Honeycomb Networks (2019)
  • Author(s): K. Kudo
  • Organizer: Research Frontier of Advanced Spectroscopies for Correlated Electron Systems
  • Int'l Joint Research / Invited
• [Presentation] Development of novel superconducting materials using polymorphism (2019)
  • Author(s): 工藤一貴
  • Organizer: 新学術領域研究「量子液晶の物性科学」キックオフミーティング
• [Presentation] Exploration of Chiral Superconductivity in Hexagonal BaPtAs and BaPtSb (2019)
  • Author(s): K. Kudo, Y. Saito, T. Takeuchi, T. Adachi, H. Ota, and M. Nohara
  • Organizer: International Conference on Strongly Correlated Electron Systems 2019 (SCES’19)
  • Int'l Joint Research
• [Presentation] Influence of Positional Fluctuations of Arsenic Atoms on Superconductivity of Pr-Substituted CaFe2As2 Revealed by X-Ray Fluorescence Holography (2019)
  • Author(s): K. Kudo, S. Ioka, N. Happo, H. Ota, Y. Ebisu, K. Kimura, T. Hada, T. Kimura, H. Tajiri, S. Hosokawa, K. Hayashi, and M. Nohara
  • Organizer: International Conference on The Strucure of Non-crystalline Materials (NCM14)
  • Int'l Joint Research
• [Presentation] Superconductivity induced by breaking dimers of IrTe2 and AuTe2 (2019)
  • Author(s): K. Kudo
  • Organizer: Pan Pacific International Symposium on Chalcogenide Functional Materials
  • Int'l Joint Research / Invited
• [Presentation] SrPtAsの角度分解光電子分光 (2019)
  • Author(s): 寺嶋健成, 片岡範行, 谷口拓海, 齋藤有紀, 工藤一貴, 野原実, 臼井秀知, 村岡祐治, 高野義彦, 横谷尚睦
  • Organizer: 日本物理学会2019年秋季大会
• [Remarks] 大阪大学大学院理学研究科物理学専攻工藤研究室ホームページ
  • URL: http://qm.phys.sci.osaka-u.ac.jp