Studies of anomalous superconducting properties near a quantum critical point by precision specific heat measurements

• Project/Area Number: 25610096
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: The University of Tokyo
• Principal Investigator: SHIBAUCHI Takasada 東京大学, 新領域創成科学研究科, 教授 (00251356)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2014: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2013: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
• Keywords: 量子臨界現象 / 超伝導特性 / 準粒子励起 / 臨界磁場 / 反強磁性 / 渦糸物理 / 有効質量 / 磁場侵入長 / 低温物性測定 / 比熱 / 超伝導 / 上部臨界磁場 / ギャップ構造 / 鉄系超伝導 / 異方的超伝導 / 下部臨界磁場 / 量子ゆらぎ / 量子臨界点

Outline of Final Research Achievements

In the vicinity of a quantum critical point, which marks a phase transition at zero temperature, physical properties exhibit deviations from the standard Fermi-liquid theory of metals, and sometimes unconventional superconductivity emerges. An important issue is to clarify the relationship between this superconductivity and the quantum critical fluctuations. In this project, we studied quasiparticle excitations in the superconducting state near a quantum critical point in iron-based superconducting materials. We found that the effective electron mass estimated from the jump in the specific heat at the superconducting transition gives a quantitative agreement with the zero-temperature penetration depth results, showing a divergent increase towards the quantum critical point. Moreover, the vortex core energy also shows an anomalous increase. These results evidence that the quantum criticality affects strongly the electronic state deep inside the superconducting phase.

Research Products

• [Journal Article] Fermi Surface of IrTe2 in the Valence-Bond State as Determined by Quantum Oscillations (2015)
  • Author(s): S. F. Blake, M. D. Watson, A. McCollam, S. Kasahara, R. D. Johnson, A. Narayanan, G. L. Pascut, K. Haule, V. Kiryukhin, T. Yamashita, D. Watanabe, T. Shibauchi, Y. Matsuda, A. I. Coldea
  • Journal Title: Physical Review B Volume: 91 Issue: 12 Pages: 121105-121105
  • DOI: 10.1103/physrevb.91.121105
  • Peer Reviewed
• [Journal Article] Emergence of Orbital Nematicity in the Tetragonal Phase of BaFe2(As1−xPx)2 (2015)
  • Author(s): T. Iye, M-H. Julien, H. Mayaffre, M. Horvatić, C. Berthier, K. Ishida, H. Ikeda, S. Kasahara,
  • Journal Title: J. Phys. Soc. Jpn Volume: 84 Issue: 4 Pages: 0437051-5
  • DOI: 10.7566/jpsj.84.043705
  • NAID: 210000133500
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Local characterization of superconductivity in BaFe2(As1-xPx)2 (2015)
  • Author(s): Yuval Lamhot, Alon Yagil, Nadav Shapira, Shigeru Kasahara, Tatsuya Watashige, Takasada Shibauchi, Yuji Matsuda, Ophir M Auslaender
  • Journal Title: Physical Review B Volume: 91 Issue: 6 Pages: 060504-060504
  • DOI: 10.1103/physrevb.91.060504
  • Peer Reviewed / Open Access
• [Journal Article] Structural Origin of the Anomalous Temperature Dependence of the Local Magnetic Moments in the CaFe2As2 Family of Materials (2015)
  • Author(s): L. Ortenzi, H. Gretarsson, S. Kasahara, Y. Matsuda, T. Shibauchi, K. D. Finkelstein, W. Wu, S. R. Julian, Y.-J. Kim, I. I. Mazin, and L. Boeri,
  • Journal Title: Phys. Rev. Lett. Volume: 114 Issue: 4 Pages: 047001-047001
  • DOI: 10.1103/physrevlett.114.047001
  • Peer Reviewed
• [Journal Article] Colossal thermomagnetic response in the exotic superconductor URu2Si2 (2015)
  • Author(s): T. Yamashita, Y. Shimoyama, Y. Haga, T.D. Matsuda, E. Yamamoto, Y. Onuki, H. Sumiyoshi, S. Fujimoto, A. Levchenko, T. Shibauchi, and Y. Matsuda
  • Journal Title: Nature Physics Volume: 11 Issue: 1 Pages: 17-20
  • DOI: 10.1038/nphys3170
  • Peer Reviewed
• [Journal Article] Anomalous Critical Fields in Quantum Critical Superconductors (2014)
  • Author(s): C. Putzke, P. Walmsley, J. D. Fletcher, L. Malone, D. Vignolles, C. Proust, S. Badoux, P. See, H. E. Beere, D. A. Ritchie, S. Kasahara, Y. Mizukami, T. Shibauchi, Y. Matsuda, and A. Carrington,
  • Journal Title: Nat. Commun. Volume: 5 Issue: 1 Pages: 5679-5679
  • DOI: 10.1038/ncomms6679
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Anisotropy of the superconducting gap in the iron-based superconductor BaFe2(As1-xPx)2 (2014)
  • Author(s): T. Yoshida, S. Ideta, T. Shimojima, W. Malaeb, H. Suzuki, I. Nishi, A. Fujimori, S. Shin, et al.
  • Journal Title: Sci. Rep. Volume: 4 Issue: 1 Pages: 7292-7292
  • DOI: 10.1038/srep07292
  • Peer Reviewed / Open Access
• [Journal Article] Disorder-Induced Topological Change of the Superconducting Gap Structure in Iron Pnictides (2014)
  • Author(s): Y. Mizukami, M. Konczykowski, Y. Kawamoto, S. Kurata, S. Kasahara, K. Hashimoto, V. Mishra, A. Kreisel, Y. Wang, P. J. Hirschfeld, Y. Matsuda, and T. Shibauchi,
  • Journal Title: Nat. Commun. Volume: 5 Issue: 1 Pages: 5657-5657
  • DOI: 10.1038/ncomms6657
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Field-Induced Superconducting Phase of FeSe in the BCS-BEC Crossover (2014)
  • Author(s): S. Kasahara, T. Watashige, T. Hanaguri, Y. Kohsaka, T. Yamashita, Y. Shimoyama, Y. Mizukami, R. Endo, H. Ikeda, K. Aoyama, T. Terashima, S. Uji, T. Wolf, H. v. Loehneysen, T. Shibauchi, Y. Matsuda
  • Journal Title: Proceedings of the National Academy of Sciences of the United States of America Volume: 111 Issue: 46 Pages: 16309-16313
  • DOI: 10.1073/pnas.1413477111
  • Peer Reviewed / Open Access
• [Journal Article] Anomalous Fermi surface in FeSe seen by Shubnikov-de Haas oscillation measurements (2014)
  • Author(s): Taichi Terashima, Naoki Kikugawa, Andhika Kiswandhi, Eun-Sang Choi, James S. Brooks, Shigeru Kasahara, Tatsuya Watashige, Hiroaki Ikeda, Takasada Shibauchi, Yuji Matsuda, Thomas Wolf, Anna E. Bohmer, Frederic Hardy, Christoph Meingast, Hilbert v. Lohneysen, Michi-To Suzuki, Ryotaro Arita, Shinya Uji
  • Journal Title: Physical Review B Volume: 90 Issue: 14 Pages: 144517-144517
  • DOI: 10.1103/physrevb.90.144517
  • Peer Reviewed
• [Journal Article] On Infrared Pseudogap in Cuprate and Pnictide High-Temperature Superconductors (2014)
  • Author(s): S. J. Moon, Y. S. Lee, A. A. Schafgans, A. V. Chubukov, S. Kasahara, T. Shibauchi, T. Terashima, Y. Matsuda, M. A. Tanatar, R. Prozorov, A. Thaler, P. C. Canfield, S. L. Bud'ko, A. S. Sefat, D. Mandrus, K. Segawa, Y. Ando, D. N. Basov,
  • Journal Title: Phys. Rev. B Volume: 90 Issue: 1 Pages: 014503-014503
  • DOI: 10.1103/physrevb.90.014503
  • Peer Reviewed
• [Journal Article] Direct Observation of Lattice Symmetry Breaking at the Hidden-Order Transition in URu2Si2 (2014)
  • Author(s): S. Tonegawa, S. Kasahara, T. Fukuda, K. Sugimoto, N. Yasuda, Y. Tsuruhara, D. Watanabe, Y. Mizukami, Y. Haga, T. D. Matsuda, E. Yamamoto, Y. Onuki, H. Ikeda, Y. Matsuda, and T. Shibauchi,
  • Journal Title: Nat. Commun. Volume: 5 Issue: 1 Pages: 4188-4188
  • DOI: 10.1038/ncomms5188
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Controllable Rashba Spin-Orbit Interaction in Artificially Engineered Superlattices Involving the Heavy-Fermion Superconductor CeCoIn_5 (2014)
  • Author(s): M. Shimozawa, et al.
  • Journal Title: Physical Review Letters Volume: 112 Issue: 15 Pages: 156404-156404
  • DOI: 10.1103/physrevlett.112.156404
  • Peer Reviewed / Open Access
• [Journal Article] Doping evolution of the quasiparticle excitations in heavily hole-doped Ba_<1-x>KxFe_2As_2 : Apossible superconducting gap with sign-reversal between hole pockets (2014)
  • Author(s): D. Watanabe, T. Yamashita, Y. Kawamoto, S. Kurata, Y. Mizukami, et al.
  • Journal Title: Physieal Review B Volume: 89 Issue: 11 Pages: 115112-115112
  • DOI: 10.1103/physrevb.89.115112
  • Peer Reviewed / Open Access
• [Journal Article] Pseudogap formation above the superconducting dome in iron pnictides (2014)
  • Author(s): T. Shimojima, T. Sonobe, W. Malaeb, K. Shinada, A. Chainani, S. Shin, T. Yoshida, S. Ideta, A. Fujimori, et al.
  • Journal Title: Phys Rev. B Volume: 89 Issue: 4 Pages: 045101-045101
  • DOI: 10.1103/physrevb.89.045101
  • Peer Reviewed
• [Journal Article] Pseudogap Formation above the Superconducting Dome in Iron-Pnictides (2014)
  • Author(s): T. Shimojima et al.
  • Journal Title: Phys. Rev. B Volume: 89 Issue: 32-33 Pages: 45101-45101
  • DOI: 10.1080/14786435.2014.887861
  • Peer Reviewed
• [Journal Article] Cyclotron Resonance Study of Quasiparticle Mass and Scattering Rate in the Hidden-Order and Superconducting Phases of URu2Si2 (2013)
  • Author(s): S. Tonegawa, K. Hashimoto, K. Ikada, Y. Tsuruhara, Y.-H. Lin, H. Shishido, Y. Haga, T. D. Matsuda, E. Yamamoto, Y. Onuki, H. Ikeda, Y. Matsuda, and T. Shibauchi
  • Journal Title: Phys. Rev. B Volume: 88 Issue: 24 Pages: 245131-245131
  • DOI: 10.1103/physrevb.88.245131
  • Peer Reviewed
• [Journal Article] Quasiparticle Mass Enhancement Close to the Quantum critical Point in BaFe_2(As_<1-x>Px)_2 (2013)
  • Author(s): P. Walmsley, C. Putzke, L. Mal0ne, I. Guillamon, D. Vignolles, C. Proust, A. I. Coldga. M. D. WatSon, S. Kasahara, Y. Mizukami, et al.
  • Journal Title: Physical Review Letter Volume: 109 Issue: 25 Pages: 257002-257002
  • DOI: 10.1103/physrevlett.110.257002
  • Peer Reviewed
• [Journal Article] Normal-state spin dynamics in the iron-pnictide superconductors BaFe_2 (A_S<1-x>P_x)_2 and Ba (Fe_<1-x>Co_x)_2AS_2 probed with NMR measurements (2013)
  • Author(s): Y. Nakai, et aL.
  • Journal Title: Physical Review B Volume: 87 Issue: 17 Pages: 174507-174507
  • DOI: 10.1103/physrevb.87.174507
  • Peer Reviewed
• [Journal Article] A Quantum Critical Point Lying beneath the Superconducting Dome in Iron-Pnictides (2013)
  • Author(s): T. Shibauchi, A. Carrington, and Y. Matsuda
  • Journal Title: Annu. Rev. Condens. Matter Phys. Volume: 5 Issue: 1 Pages: 113-135
  • DOI: 10.1146/annurev-conmatphys-031113-133921
  • Peer Reviewed / Open Access
• [Presentation] Quantum criticality and BCS-BEC crossover in iron-based superconductors (2014)
  • Author(s): T. Shibauchi
  • Organizer: KITP Conference on Strong Correlations and Unconventional Superconductivity: Towards a Conceptual Framework
  • Place of Presentation: Santa Barbara, CA, USA
  • Year and Date: 2014-09-22 – 2014-09-26
  • Invited
• [Presentation] URu2Si2の隠れた秩序とエキゾチック超伝導 (2014)
  • Author(s): 芝内孝禎
  • Organizer: 日本物理学会2014年秋季大会 領域8シンポジウム「重い電子系化合物の新展開」
  • Place of Presentation: 中部大学(愛知県春日井市）
  • Year and Date: 2014-09-07 – 2014-09-10
  • Invited
• [Presentation] Quantum criticality in iron pnictide superconductors (2014)
  • Author(s): T. Shibauchi
  • Organizer: 27th International Conference on Low Temperature Physics (LT27)
  • Place of Presentation: Buenos Aires, Argentina
  • Year and Date: 2014-08-06 – 2014-08-13
  • Invited
• [Presentation] 反強磁性量子臨界揺らぎと超伝導 (2014)
  • Author(s): 芝内孝禎
  • Organizer: 東北大金研ワークショップ「多自由度が協奏する分子システムの科学」
  • Place of Presentation: 東北大学金属材料研究所(仙台市）
  • Year and Date: 2014-07-18 – 2014-07-20
  • Invited
• [Presentation] Quantum criticality and unconventional superconductivity in iron-pnictides (2014)
  • Author(s): T. Shibauchi
  • Organizer: ISSP workshop on "New Horizon of Strongly Correlated Physics" (NHSCP2014)
  • Place of Presentation: 東京大学物性研究所(柏市）
  • Year and Date: 2014-06-25 – 2014-06-27
  • Invited
• [Presentation] Symmetry Breaking in the Hidden-Order Phase of URu2Si2 (2014)
  • Author(s): T. Shibauchi
  • Organizer: REIMEI Workshop on "Electronic state of URu2Si2 and related systems"
  • Place of Presentation: 日本原子力研究機構(東海）
  • Year and Date: 2014-06-23
  • Invited
• [Presentation] The Superconducting Order Parameter in Iron-based Superconductors (2014)
  • Author(s): T. Shibauchi
  • Organizer: International Conferences on Modern Materials and Technologies (CIMTEC 2014), 7th International Conference on Science and Engineering of Novel Superconductors
  • Place of Presentation: Montecatini Terme, Italy
  • Year and Date: 2014-06-16 – 2014-06-19
  • Invited
• [Presentation] Quantum Criticality in Iron-pnictide Superconductors (2014)
  • Author(s): T. Shibauchi
  • Organizer: RIKEN-APW joint workshop ``Highlights in condensed matter physics"
  • Place of Presentation: 和光市理化学研究所
  • Invited
• [Presentation] 電子状態相図と不純物効果 (2014)
  • Author(s): 芝内孝禎
  • Organizer: 日本物理学会 第69回年次大会
  • Place of Presentation: 東海大学湘南キャンパス
  • Invited
• [Presentation] Symmetry Breaking in the Hidden-Order Phase of URu2Si2 (2013)
  • Author(s): T. Shibauchi
  • Organizer: Lorentz Center Workshop on Hidden Order, Superconductivity, and Magnetism in URu2Si2
  • Place of Presentation: Leiden, the Netherlands
  • Invited
• [Presentation] Exotic Superconductivity of Heavy Electrons in Artificial Two-Dimensional Kondo Lattices (2013)
  • Author(s): T. Shibauchi
  • Organizer: International Conference on Electron Correlation in Nanostructures (ECN-2013)
  • Place of Presentation: Yalta, Ukraine
  • Invited
• [Presentation] Electronic phase diagram of iron-pnictide superconductor BaFe2(As1-xPx)2 (2013)
  • Author(s): T. Shibauchi
  • Organizer: The IUMRS International Conference on Advanced Materials (IUMRS-ICAM2013): Advanced superconducting materials and its applications
  • Place of Presentation: Qingdao, China
  • Invited
• [Presentation] Superconducting Gap Symmetry in BaFe2As2-Based Superconductors (2013)
  • Author(s): T. Shibauchi
  • Organizer: International Workshop on Recent Developments in Fe-based high-temperature Superconductors
  • Place of Presentation: Riverhead, New York, USA
  • Invited
• [Presentation] Symmetry Breaking in the Hidden-Order Phase of URu2Si2 (2013)
  • Author(s): T. Shibauchi
  • Organizer: The International Conference on Strongly Correlated Electron Systems (SCES 2013)
  • Place of Presentation: Tokyo, Japan
  • Invited
• [Presentation] Nematic Transition and Antiferromagnetic Quantum Critical Point in BaFe2(As1-xPx)2 (2013)
  • Author(s): T. Shibauchi
  • Organizer: Spectroscopies in Novel Superconductors (SNS2013)
  • Place of Presentation: Berkeley, California, USA
  • Invited
• [Remarks] 超伝導ゆらぎによる巨大熱磁気効果の発見
  • URL: http://www.k.u-tokyo.ac.jp/info/entry/22_entry351/
• [Remarks] 鉄系高温超伝導の発現機構を解く鍵となる電子状態を解明
  • URL: http://www.k.u-tokyo.ac.jp/info/entry/22_entry350/
• [Remarks] 「ボース・アインシュタイン凝縮に最も近い超伝導状態」を発見
  • URL: http://www.k.u-tokyo.ac.jp/info/entry/22_entry344/
• [Remarks] 直接観測された物質物理学の謎「隠れた秩序」
  • URL: http://www.k.u-tokyo.ac.jp/info/entry/22_entry314/
• [Remarks] 研究紹介
  • URL: http://qpm.k.u-tokyo.ac.jp/index.php?%E7%A0%94%E7%A9%B6%E7%B4%B9%E4%BB%8B