Angle-resolved photoemission spectroscopy study of superconducting mechanism and electronic phase diagram in iron-based superconductors

• Project/Area Number: 24740215
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: Tohoku University
• Principal Investigator: NAKAYAMA Kosuke 東北大学, 理学(系)研究科(研究院), 助教 (40583547)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2014: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2013: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2012: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
• Keywords: 光電子分光 / 高温超伝導 / 鉄系超伝導体 / 電子状態

Outline of Final Research Achievements

In order to clarify the superconducting mechanism of iron-based superconductors, we have improved an ultrahigh-resolution photoemission spectrometer. By using this apparatus, we have performed systematic photoemission spectroscopy study of the electronic structure in various iron-based superconductors. The obtained results suggest an important role of spin fluctuations for the superconductivity. Our results also provide new insights into the electronic phase diagrams of iron-based superconductors. Besides performing photoemission, we have fabricated thin films of iron selenide and succeeded in converting non-superconducting multilayer films into high-temperature superconductors as a consequence of successful electron doping.

Research Products

• [Journal Article] Evolution from incoherent to coherent electronic states and its implications to superconductivity in FeTe1-xSex (2014)
  • Author(s): E. Ieki, K. Nakayama, Y. Miyata, T. Sato, H. Miao, N. Xu, X.-P. Wang, P. Zhang, T. Qian, P. Richard, Z.-J. Xu, J. S. Wen, G. D. Gu, H. Q. Luo, H.-H. Wen, H. Ding, and T. Takahashi
  • Journal Title: Phys. Rev. B Volume: 89 Issue: 14
  • DOI: 10.1103/physrevb.89.140506
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Reconstruction of Band Structure Induced by Electronic Nematicity in an FeSe Superconductor (2014)
  • Author(s): K. Nakayama, Y. Miyata, G. N. Phan, T. Sato, Y. Tanabe, T. Urata, K. Tanigaki, and T. Takahashi
  • Journal Title: Physical Review Letters Volume: 113 Issue: 23
  • DOI: 10.1103/physrevlett.113.237001
  • Peer Reviewed
• [Journal Article] Possible nodal superconducting gap and Lifshitz transition in heavily hole-doped Ba0.1K0.9Fe2As2 (2013)
  • Author(s): N. Xu, P. Richard, X. Shi, A. van Roekeghem, T. Qian, E. Razzoli, E. Rienks, G.-F. Chen, E. Ieki, K. Nakayama, T. Sato, T. Takahashi, M. Shi, and H. Ding
  • Journal Title: Physical Review B Volume: 88 Issue: 22
  • DOI: 10.1103/physrevb.88.220508
  • Peer Reviewed
• [Journal Article] Electronic structure of the iron chalcogenide KFeAgTe2 revealed by angle-resolved photoemission spectroscopy (2013)
  • Author(s): R. Ang, K. Nakayama, W.-G. Yin, T. Sato, Hechang Lei, C. Petrovic, and T. Takahashi
  • Journal Title: Physical Review B Volume: 88 Issue: 15 Pages: 155102-155102
  • DOI: 10.1103/physrevb.88.155102
  • Peer Reviewed
• [Journal Article] Superconductivity and bandwidth-controlled Mott metal-insulator transition in 1T-TaS2－x Sex (2013)
  • Author(s): R. Ang, Y. Miyata, E. Ieki, K. Nakayama, T. Sato, Y. Liu, W. J. Lu, Y. P. Sun, and T. Takahashi
  • Journal Title: Physical Review B Volume: 88 Issue: 11 Pages: 115145-115145
  • DOI: 10.1103/physrevb.88.115145
  • Peer Reviewed
• [Journal Article] Angle-resolved photoemission observation of isotropic superconducting gaps in isovalent Ru-substituted Ba(Fe0.75Ru0.25)2As2 (2013)
  • Author(s): N. Xu et al.
  • Journal Title: Phys. Rev. B Volume: 87 Issue: 9 Pages: 94513-94513
  • DOI: 10.1103/physrevb.87.094513
  • Peer Reviewed
• [Journal Article] Co-Based Boride Superconductor LaCo_2B_2: Similar to or Different from Fe-Based Pnitctide Superconductor? (2012)
  • Author(s): K. Nakayama, E. Ieki, Y. Tanaka, T. Sato, T.Takahashi, T. Kuroda, H. Mizoguchi, S. W. Kim, and H. Hosono
  • Journal Title: Phys. Rev. B Volume: vol. 86 Issue: 1 Pages: 14503-14503
  • DOI: 10.1103/physrevb.86.014503
  • Peer Reviewed
• [Journal Article] Real-Space Coexistence of Melted Mott phase and Superconductivity in Fe-Substituted 1T-TaS_2 (2012)
  • Author(s): A. Ran, et al.
  • Journal Title: Physical Review Letters Volume: 109 Issue: 17 Pages: 176403-176403
  • DOI: 10.1103/physrevlett.109.176403
  • Peer Reviewed
• [Presentation] Electronic nematicity and unconventional superconductivity in FeSe (2015)
  • Author(s): K. Nakayama, Y. Miyata, G. N. Phan, T. Sato, Y. Tanabe, T. Urata, K. Tanigaki, and T. Takahashi
  • Organizer: Materials and Mechanisms of Superconductivity 2015
  • Place of Presentation: Geneva
  • Year and Date: 2015-08-23 – 2015-08-28
• [Presentation] High-resolution ARPES study of strain effects on the electronic structure of FeSe (2015)
  • Author(s): G. N. Phan, K. Nakayama, Y. Miyata, K. Sugawara, T. Sato, Y. Tanabe, T. Urata, K. Tanigaki, F. Nabeshima, Y. Imai, A. Maeda, and T. Takahashi
  • Organizer: Materials and Mechanisms of Superconductivity 2015
  • Place of Presentation: Geneva
  • Year and Date: 2015-08-23 – 2015-08-28
• [Presentation] FeSe超薄膜の高分解能ARPES (2015)
  • Author(s): 中山耕輔、宮田康成、Giao Phan、菅原克明、佐藤宇史、高橋 隆
  • Organizer: 日本物理学会 第70回年次大会
  • Place of Presentation: 早稲田大学(西早稲田)
  • Year and Date: 2015-03-21 – 2015-03-24
• [Presentation] High-resolution ARPES study of Fe1-xCoxSe (2015)
  • Author(s): Giao Phan, Yasunari Miyata, Kosuke Nakayama, Takafumi Sato, Yoichi Tanabe, Takahiro Urata, Katsumi Tanigaki, Takashi Takahashi
  • Organizer: 日本物理学会 第70回年次大会
  • Place of Presentation: 早稲田大学(西早稲田)
  • Year and Date: 2015-03-21 – 2015-03-24
• [Presentation] 鉄カルコゲナイド超伝導体の高分解能ARPES (2015)
  • Author(s): 中山耕輔、家城 英、宮田康成、Giao Phan、佐藤宇史、田邊洋一、浦田隆広、谷垣勝己、高橋 隆
  • Organizer: 第28回日本放射光学会年会
  • Place of Presentation: 立命館大学(草津)
  • Year and Date: 2015-01-10 – 2015-01-12
• [Presentation] FeSe単結晶の高分解能ARPES (2014)
  • Author(s): 中山耕輔、宮田康成、Giao Phan、佐藤宇史、 田邊洋一、浦田隆広、谷垣勝己、高橋 隆
  • Organizer: 日本物理学会 2014年秋季大会
  • Place of Presentation: 中部大学(春日井)
  • Year and Date: 2014-09-07 – 2014-09-10
• [Presentation] 単層および多層FeSe薄膜の高分解能ARPES (2014)
  • Author(s): 宮田康成、Giao Phan、中山耕輔、菅原克明、佐藤宇史、高橋 隆
  • Organizer: 日本物理学会 2014年秋季大会
  • Place of Presentation: 中部大学(春日井)
  • Year and Date: 2014-09-07 – 2014-09-10
• [Presentation] Strain effects on the electronic structure of FeSe (2014)
  • Author(s): Giao Phan, Yasunari Miyata, Kosuke Nakayama, Katsuaki Sugawara, Takafumi Sato, Takashi Takahashi, Youichi Tanabe, Takahiro Urata, Katsumi Tanigaki, Fuyuki Nabeshima, Yoshinori Imai, Atsutaka Maeda
  • Organizer: 日本物理学会 2014年秋季大会
  • Place of Presentation: 中部大学(春日井)
  • Year and Date: 2014-09-07 – 2014-09-10
• [Presentation] FeSe薄膜の電子状態：高分解能ARPES (2014)
  • Author(s): 中山耕輔、宮田康成、家城英、菅原克明、佐藤宇史、高橋隆
  • Organizer: 日本物理学会 第69回年次大会
  • Place of Presentation: 東海大学 (神奈川県平塚市)
• [Presentation] FeSe/SrTiO3の高分解能ARPES (2014)
  • Author(s): 宮田康成、家城英、中山耕輔、菅原克明、佐藤宇史、高橋隆
  • Organizer: 日本物理学会 第69回年次大会
  • Place of Presentation: 東海大学 (神奈川県平塚市)
• [Presentation] High-resolution ARPES of FeSe film (2014)
  • Author(s): G. Phan, Y. Miyata, E. Ieki, K. Nakayama, T. Sato, T. Takahashi, F. Nabeshima, Y. Imai, A. Maeda
  • Organizer: 日本物理学会 第69回年次大会
  • Place of Presentation: 東海大学 (神奈川県平塚市)
• [Presentation] High-resolution ARPES study of iron-based superconductors (2013)
  • Author(s): Kosuke Nakayama
  • Organizer: ICC-IMR international workshop
  • Place of Presentation: 東北大学金属材料研究所 (宮城県仙台市)
  • Invited
• [Presentation] Evolution of low-energy electronic states in an iron-chalcogenide superconductor studied by high-resolution ARPES (2013)
  • Author(s): K. Nakayama, E. Ieki, Y. Tanaka, T. Sato, H. Miao, T. Qian, P. Richard, H. H. Wen, G. D. Gu, H. Ding, and T. Takahashi
  • Organizer: Spectroscopy of Novel Superconductors 2013
  • Place of Presentation: Lawrence Berkeley National Lab (Berkeley, USA)
• [Presentation] Doping evolution of electronic states in LiFeAs studied by high-resolution ARPES (2013)
  • Author(s): Y. Miyata, X.-P. Wang, E. Ieki, K. Nakayama, T. Sato, P. Richard, H. Ding, and T. Takahashi
  • Organizer: Spectroscopy of Novel Superconductors 2013
  • Place of Presentation: Lawrence Berkeley National Lab (Berkeley, USA)
• [Presentation] NaFeAs系超伝導体の高分解能ARPES (2013)
  • Author(s): 中山耕輔、宮田康成、家城英、佐藤宇史、T. Qian、P. Richard、H. Ding、Z.-H. Liu、S.-C. Wang、高橋隆
  • Organizer: 日本物理学会 2013年秋季大会
  • Place of Presentation: 徳島大学 (徳島県徳島市)
• [Presentation] Seを過剰置換したFeTe1-xSexの高分解能ARPES (2013)
  • Author(s): 家城英、宮田康成、中山耕輔、佐藤宇史、H. Miao、T. Qian、P. Richard、H. H. Wen、G. D. Guo、H. Ding、高橋隆
  • Organizer: 日本物理学会 2013年秋季大会
  • Place of Presentation: 徳島大学 (徳島県徳島市)
• [Presentation] 電子ドープ型LiFeAsの高分解能ARPES (2013)
  • Author(s): 宮田康成、X.-P. Wang、家城英、中山耕輔、佐藤宇史、H. Miao、P. Richard、H. Ding、Y. Liu、Z.-H. Liu、S.-C. Wang、高橋隆
  • Organizer: 日本物理学会 2013年秋季大会
  • Place of Presentation: 徳島大学 (徳島県徳島市)
• [Presentation] Low-energy electronic excitations in iron-based superconductors studied by ARPES (2012)
  • Author(s): Kosuke Nakayama
  • Organizer: WPI-AIMR Mini Workshop "A route to high Tc superconductivity"
  • Place of Presentation: 東北大学原子分子材料科学高等研究機構
  • Invited
• [Presentation] 新型コバルト系超伝導体LaCo2B2の高分解能ARPES (2012)
  • Author(s): 家城 英、中山耕輔、田中祐輔、相馬清吾、佐藤宇史、 高橋 隆、黒田稔顕、溝口 拓、金 聖雄、細野秀雄
  • Organizer: 日本物理学会2012年秋季大会
  • Place of Presentation: 横浜国立大学
• [Presentation] FeTe1-xSexの電子状態の組成依存性:高分解能ARPES (2012)
  • Author(s): 家城 英、田中祐輔、中山耕輔、佐藤宇史、H. Miao、 T. Qian、P. Richard、H. H. Wen、G. D. Gu、高橋 隆
  • Organizer: 日本物理学会2012年秋季大会
  • Place of Presentation: 横浜国立大学
• [Presentation] オーバードープBa1-xKxFe2As2の超伝導ギャップ：高分解能ARPES (2012)
  • Author(s): 中山耕輔、家城 英、佐藤宇史、H. Miao、T. Qian、P. Richard、Y.-M. Xu、M. Neupane、G. F. Chen、H. Ding、高橋 隆
  • Organizer: 日本物理学会2012年秋季大会
  • Place of Presentation: 横浜国立大学
• [Presentation] FeTe1-xSex超伝導体の高分解能ARPES (2012)
  • Author(s): 家城 英、宮田康成、田中祐輔、中山耕輔、佐藤宇史、H. Miao、T. Qian、P. Richard、H. H. Wen、G. D. Gu、H. Ding、高橋 隆
  • Organizer: 日本物理学会2012年秋季大会
  • Place of Presentation: 横浜国立大学
• [Presentation] Co置換LiFeAs超伝導体の高分解能ARPES (2012)
  • Author(s): 宮田 康成、X.-P. Wang、家城 英、中山 耕輔、佐藤 宇史、P. Richard、H. Ding、高橋 隆
  • Organizer: 日本物理学会2012年秋季大会
  • Place of Presentation: 横浜国立大学