クラスター構造をもつ準結晶における多極子伝導系の研究

• Project Area: J-Physics: Physics of conductive multipole systems
• Project/Area Number: 16H01071
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: Nagoya University
• Principal Investigator: 出口 和彦 名古屋大学, 理学研究科, 講師 (40397584)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥8,580,000 (Direct Cost: ¥6,600,000、Indirect Cost: ¥1,980,000); Fiscal Year 2017: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2016: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
• Keywords: 強相関電子系 / 低温物性 / 金属物性 / 磁性 / 超伝導

Outline of Annual Research Achievements

強相関電子系における並進対称性（大きな構造として周期性・準周期性）の役割の解明するため、電子状態の特異性が顕著に表れる希土類を含むTsai-typeクラスター構造をもつ量子臨界物質Au-Al-Yb準結晶・近似結晶や超伝導物質のような強相関電子系準結晶の物性について同じ局所構造を持つ準結晶（準周期）・近似結晶（周期）を作成し、対照実験を行い、準結晶特有の強相関電子物性を明らかにする研究を進めた。
（１）前年の研究でAu-Al-Yb準結晶が静水圧に対し「硬い」量子臨界物質であることと対照的に、Au-Al-Yb近似結晶は圧力に「敏感な」重い電子系の近似結晶であること発見した。そこで、Yb原子の配位原子を置換により変化させて、元素置換効果に着目して準結晶に特有の物性を調べた。Au(Al)をCu(Ga)に部分置換した(Au,Cu)-Al-Yb、Au-(Al,Ga)-Yb準結晶でも準結晶の量子臨界現象は置換効果(化学圧力)に対して「硬さ」を示すことが明らかとなり、準結晶特有の電子状態がAu-Al-Yb準結晶の量子臨界現象・磁性と密接に結びついていることがわかった。
（２）Au-Ge-Yb近似結晶の超伝導の研究を一歩進め、Al-Mg-Zn準結晶において50mKでバルクの超伝導が発現することを明らかにして、準結晶の超伝導の研究の端緒をつかんだ。Nature Communicationsに論文発表し[1]、“ノーベル賞間違いなし、日本発「準結晶超伝導転移」”(伊東 乾, JBpress)のようにニュースとして取り上げられた。
[1] “Discovery of Superconductivity in Quasicrystal” K. Kamiya, K. Deguchi et al., Nature Communications 9, 154 (2018).

Research Progress Status

29年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

29年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] Discovery of superconductivity in quasicrystals (2018)
  • Author(s): K. Kamiya, T. Takeuchi, N. Kabeya, N. Wada, T. Ishimasa, A. Ochiai, K. Deguchi, K. Imura, N.K. Sato
  • Journal Title: Nature Communications Volume: 9 Issue: 1 Pages: 154-154
  • DOI: 10.1038/s41467-017-02667-x
  • Peer Reviewed / Open Access
• [Journal Article] First Observation of Heavy Fermion Behavior in Ce-Based Icosahedral Approximant (2017)
  • Author(s): K. Imura, K. Nobe, K. Deguchi, M. Matsunami, H. Miyazaki, A. Yasui, E. Ikenaga, N. K. Sato
  • Journal Title: J. Phys. Soc. Jpn. Volume: 86 Issue: 9 Pages: 093702-093702
  • DOI: 10.7566/jpsj.86.093702
  • NAID: 210000134491
  • Peer Reviewed
• [Journal Article] Quantum critical behavior in magnetic quasicrystals and approximant crystals (2017)
  • Author(s): N. K. Sato, S.Matsukawa, K. Nobe, K. Imura, K. Deguchi, T. Ishimasa
  • Journal Title: J. Physics Conf. Series Volume: 868 Pages: 012005-012005
  • DOI: 10.1088/1742-6596/868/1/012005
  • Peer Reviewed / Open Access
• [Journal Article] Direct observation of heterogeneous valence state in Yb-based quasicrystalline approximants (2017)
  • Author(s): M. Matsunami, M. Oura, K. Tamasaku, T. Ishikawa, S. Ideta, K. Tanaka, T. Takeuchi, T. Yamada, A.P. Tsai, K. Imura, K. Deguchi, N.K. Sato, T. Ishimasa
  • Journal Title: Physical Review B Volume: 96 Issue: 24
  • DOI: 10.1103/physrevb.96.241102
  • Peer Reviewed
• [Journal Article] Discovery of Quantum-Criticality-Like Behavior in Dilute Kondo System:CexLa1－xCu5.62Au0.38 (2017)
  • Author(s): T. Shiino, Y. Shinagawa, K. Imura, K. Deguchi, N. K. Sato
  • Journal Title: J. Phys. Soc. Jpn. Volume: 86 Issue: 12 Pages: 123705-123705
  • DOI: 10.7566/jpsj.86.123705
  • Peer Reviewed / Open Access
• [Journal Article] Observation of Systematic Variation in Yb Ion Valence as a Function of Interatomic Spacing in Icosahedral Approximant Crystals (2017)
  • Author(s): M. Hayashi, K. Deguchi, S. Matsukawa, K. Imura, and N. K. Sato
  • Journal Title: Journal of the Physical Society of Japan Volume: 86 Issue: 4 Pages: 043702-043702
  • DOI: 10.7566/jpsj.86.043702
  • NAID: 210000134324
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Magnetic Properties of the Au-Al-Yb Approximant under Hydrostatic Pressure (2017)
  • Author(s): S. Matsukawa, K. Deguchi, K. Imura, T. Ishimasa, and N. K. Sato
  • Journal Title: Journal of Physics: Conf. Series Volume: 809 Pages: 012013-012013
  • DOI: 10.1088/1742-6596/809/1/012013
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Anticorrelation between polar lattice instability and superconductivity in the Weyl semimetal candidate MoTe2 (2017)
  • Author(s): H. Takahashi, T. Akiba, K. Imura, T. Shiino, K. Deguchi, N. K. Sato, H. Sakai, M. S. Bahramy, and S. Ishiwata
  • Journal Title: Phys. Rev. B Volume: 95 Issue: 10
  • DOI: 10.1103/physrevb.95.100501
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Aging effects of dodecagonal quasicrystal formed in Mn-Cr-Ni-Si alloys (2017)
  • Author(s): K. Toyonaga, and T. Ishimasa
  • Journal Title: Journal of Physics: Conf. Series Volume: 809 Pages: 012015-012015
  • DOI: 10.1088/1742-6596/809/1/012015
  • Peer Reviewed
• [Journal Article] Pressure-Driven Quantum Criticality and T/H Scaling in the Icosahedral Au-Al-Yb Approximant (2016)
  • Author(s): S. Matsukawa, K. Deguchi, K. Imura, T. Ishimasa, and Noriaki K. Sato
  • Journal Title: Journal of the Physical Society of Japan Volume: 85 Issue: 6 Pages: 063706-063706
  • DOI: 10.7566/jpsj.85.063706
  • NAID: 40020851813
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Mysteries of icosahedral quasicrystals: how are the atoms arranged ? (2016)
  • Author(s): T. Ishimasa
  • Journal Title: IUCrJ Volume: 3 Issue: 4 Pages: 230-231
  • DOI: 10.1107/s2052252516009842
  • Peer Reviewed
• [Presentation] 量子臨界現象と高次元性 (2018)
  • Author(s): 出口和彦
  • Organizer: 日本物理学会
  • Invited
• [Presentation] 正20面体準結晶の磁性と超伝導 (2018)
  • Author(s): 出口和彦
  • Organizer: J-Physics：多極子伝導系の物理 平成29年度領域全体会議
• [Presentation] Au-Ga-Yb準結晶・近似結晶の磁性と電子状態 (2018)
  • Author(s): 出口和彦, 廣川慎之介, 米山祐樹, 横田晋次郎, 坂本和司、井村敬一郎, 佐藤憲昭, 豊永詞, 石政勉, 山本義哉, 川井拓真, 水木純一郎, 山岡人志, 平岡望, 石井啓文
  • Organizer: 第２２回準結晶研究会
• [Presentation] Tsai型クラスター構造をもつAu-Al-Yb準結晶の置換効果 (2017)
  • Author(s): 出口和彦, 難波慶介, 松川周矢, 廣川慎之介, 米山祐樹, 井村敬一郎, 石政勉, 佐藤憲昭
  • Organizer: 日本物理学会
  • Place of Presentation: 大阪大学
  • Year and Date: 2017-03-17
• [Presentation] Tsai 型クラスター構造をもつAu-Al-Yb 準結晶の置換効果(II) (2017)
  • Author(s): 出口和彦, 難波慶介, 松川周矢, 廣川慎之介, 米山祐樹, 横田晋次郎,井村敬一郎, 佐藤憲昭, 豊永詞, 石政勉, 山本義哉, 山岡人志, 平岡望, 石井啓文
  • Organizer: 第２１回準結晶研究会
  • Place of Presentation: 北海道大学
  • Year and Date: 2017-03-02
• [Presentation] Quantum Criticality and Superconductivity in icosahedral Yb quasicrystals and approximants (2017)
  • Author(s): Kazuhiko Deguchi
  • Organizer: Open space between aperiodic order and strong electronic correlations
  • Int'l Joint Research / Invited
• [Presentation] Magnetic quasicrystal with Yb icosahedron (2017)
  • Author(s): Kazuhiko Deguchi
  • Organizer: J-Physics 2017: International Workshop on Multipole Physics and Related Phenomena
  • Int'l Joint Research / Invited
• [Presentation] 中間価数のYbをもつ磁気準結晶・近似結晶 (2017)
  • Author(s): 出口和彦
  • Organizer: J-Physicsトピカルミーティング「局在多極子と伝導電子の相関による新現象」
  • Invited
• [Presentation] Physics hidden in open space between heavy fermions and quasicrystals (2016)
  • Author(s): Noriaki K. Sato
  • Organizer: 13th International conference on quasicrystals (ICQ13)
  • Place of Presentation: Dhulikhel Lodge Resort (Kathmandu, Nepal)
  • Year and Date: 2016-09-18
  • Int'l Joint Research / Invited
• [Presentation] Magnetism and superconductivity in icosahedral quasicrystals and approximants with Tsai-type clusters (2016)
  • Author(s): K. Deguchi
  • Organizer: 13th International conference on quasicrystals (ICQ13)
  • Place of Presentation: Dhulikhel Lodge Resort (Kathmandu, Nepal)
  • Year and Date: 2016-09-18
  • Int'l Joint Research
• [Presentation] Dodecagonal quasicrystal in Mn-based alloy (2016)
  • Author(s): T. Ishimasa
  • Organizer: 13th International conference on quasicrystals (ICQ13)
  • Place of Presentation: Dhulikhel Lodge Resort (Kathmandu, Nepal)
  • Year and Date: 2016-09-18
  • Int'l Joint Research
• [Presentation] クラスター構造をもつ正20面体準結晶・近似結晶の磁性と超伝導 (2016)
  • Author(s): 出口和彦
  • Organizer: J-Physics：多極子伝導系の物理 平成28年度領域全体会議
  • Place of Presentation: 北海道大学
  • Year and Date: 2016-05-26
• [Presentation] Quantum Criticality and Superconductivity in Icosahedral Quasicrystals and Approximants with Tsai-type Clusters (2016)
  • Author(s): K. Deguchi
  • Organizer: The International Conference on Strongly Correlated Electron Systems (SCES2016)
  • Place of Presentation: Zhejiang University (Hangzhou, China)
  • Year and Date: 2016-05-08
  • Int'l Joint Research / Invited