Superconductivity mechanism of molecular conductors through control of the dimerization and frustration

2012 Fiscal Year Final Research Report

• Project/Area Number: 22540365
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Nagoya University
• Principal Investigator: ITO Hiroshi 名古屋大学, 工学研究科, 准教授 (10260374)
• Co-Investigator(Kenkyū-buntansha): ONARI Seiichiro 名古屋大学, 大学院・工学研究科, 助教 (80402535)
• Project Period (FY): 2010 – 2012
• Keywords: 有機超伝導体 / 2量体化 / β型分子配列 / スピン揺らぎ / 三角格子 / フラストレーション / 一軸圧縮

Research Abstract

We study experimentally and theoretically the shift of the superconducting transition temperature (T_C) under uniaxial compression in β-type organic superconductors possessing unidirectional molecular stacks. Contrary to the BDA-TTP salts, BEDT-TTF salts shows T_C maximum in both compressions parallel and perpendicular to the molecular stack. T_C calculations are carried out on both the dimerized and nondimerized Hubbard models. We have found that the competition between the spin frustration and the effect induced by the fluctuation causes the nonmonotonic shift of T_C and that the behavior of T_C in BEDT-TTF salts with a stronger dimerization is well reproduced by the dimer model, while that in weakly dimerized BDA-TTP salts is rather well reproduced by the nondimerized model.

Research Products

• [Journal Article] Superconducting Pairing Symmetry on the Extended Hubbard Model in the Presence of the Rashba-Type Spin-Orbit Coupling (2013)
  • Author(s): K. Shigeta, S. Onari, and Y. Tanaka
  • Journal Title: J. Phys. Soc. Jpn. Volume: 82 Pages: 104702_1-9
  • DOI: DOI:10.7566/JPSJ.82.014702
  • Peer Reviewed
• [Journal Article] New BDH-TTP/[M^III(C_5O_5)_3]^3- (M = Fe, Ga) Isostructural Molecular Metals (2013)
  • Author(s): L. Pilia, E. Sessini, F. Artizzu, M. Yamashita, A. Serpe, K. Kubo, H. Ito, H. Tanaka, S. Kuroda, J. Yamada, P. Deplano, C. J. Gomez-Garcia, and M. L. Mercuri
  • Journal Title: Inorg. Chem. Volume: 52 Pages: 423-430
  • DOI: DOI:10.1021/ic302234j
  • Peer Reviewed
• [Journal Article] Symmetry of superconducting pairing state in a staggered field (2012)
  • Author(s): K. Shigeta, S. Onari, and Y. Tanaka
  • Journal Title: Phys. Rev. B Volume: 85 Pages: 1-13
  • DOI: DOI:10.1103/PhysRevB.85.224509
  • Peer Reviewed
• [Journal Article] Variable-Range Hopping Conduction in Ion-Gel-Gated Electrochemical Transistors of Regioregular Poly(3-hexylthiophene) (2012)
  • Author(s): Y. Ando, H. Ito, S. Watanabe, and S. Kuroda
  • Journal Title: J. Phys. Soc. Jpn. Volume: 81 Pages: 1-4
  • DOI: DOI:10.1143/JPSJ.81.114721
  • Peer Reviewed
• [Journal Article] Competition of pairing symmetries and a mechanism for Berezinskii pairing in quasi-one-dimensional systems (2011)
  • Author(s): K. Shigeta, Y. Tanaka, K. Kuroki, S. Onari, and H. Aizawa
  • Journal Title: Phys. Rev. B Volume: 83 Pages: 1-4
  • DOI: DOI:10.1103/PhysRevB.83.140509
  • Peer Reviewed
• [Journal Article] Theory of the β-type organic superconductivity under uniaxial compression (2011)
  • Author(s): T. Suzuki, S. Onari, H. Ito, and Y. Tanaka
  • Journal Title: J. Phys. Soc. Jpn. Volume: 80 Pages: 1-8
  • DOI: DOI:10.1143/JPSJ.80.094704
  • Peer Reviewed
• [Journal Article] Superconductivity of β-Type Salts under Uniaxial Compression (2010)
  • Author(s): H. Ito, T. Ishihara, M. Niwa, T. Suzuki, S. Onari, Y. Tanaka, J. Yamada, H. Yamochi, and G. Saito
  • Journal Title: Physica B Volume: 405 Pages: S262-S264
  • DOI: DOI:10.1016/j.physb.2009.12.073
  • Peer Reviewed
• [Presentation] イオンゲルトランジスタによるBEDT-TTF錯体単結晶へのキャリア注入 (2013)
  • Author(s): 井口聖悟,安藤良洋,伊東裕,黒田新一,平松孝章,吉田幸大,齋藤軍治
  • Organizer: 日本物理学会第68回年次大会
  • Place of Presentation: 広島大学
  • Year and Date: 20130326-29
• [Presentation] 高移動度導電性高分子PBTTTイオンゲルトランジスタの可変領域ホッピング伝導 (2013)
  • Author(s): 伊東裕,安藤良洋,渡辺峻一郎,黒田新一
  • Organizer: 日本物理学会第68回年次大会
  • Place of Presentation: 広島大学 (東広島市)
  • Year and Date: 20130326-29
• [Presentation] Variable-Range Hopping Transport in Ion Gel-Gated Electrochemical Transistors of Regioregular Conjugated Polymers (2012)
  • Author(s): H. Ito, Y. Ando, S. Watanabe, H. Tanaka, and S. Kuroda
  • Organizer: IUMRS-International Conference on Electronic Materials (IUMRS-ICEM 2012)
  • Place of Presentation: 横浜国際会議場 (横浜市)
  • Year and Date: 20120923-28
• [Presentation] 有機超伝導体 β-(ET)2IBr2の一軸性圧縮効果 (2012)
  • Author(s): 浅井貴行,伊東裕,田中久暁,黒田新一,鈴木丈夫,大成誠一郎,田仲由喜夫,平松孝章,齋藤軍治,矢持秀起
  • Organizer: 日本物理学会2012年秋季大会
  • Place of Presentation: 横浜国立大学 (横浜市)
  • Year and Date: 20120918-21
• [Presentation] Variable-range hopping conduction behavior in ion gel-gated thin-film transistors of regioregular poly(3-hexylthiophene) (2012)
  • Author(s): H. Ito, Y. Ando, S. Watanabe, S. Kuroda
  • Organizer: International Conference on Science and Technology of Synthetic Metals (ICSM 2012)
  • Place of Presentation: Atlanta, USA
  • Year and Date: 20120708-13
• [Presentation] Pressure and field-effect control of (super)conducting properties of organic crystals and polymers (2012)
  • Author(s): H. Ito
  • Organizer: International workshop on Multifunctional Molecular Materials Based on Triangular Lattice
  • Place of Presentation: 京都大学(京都市)
  • Year and Date: 2012-02-17
• [Presentation] β型有機超伝導体の一軸性圧縮効果‐圧縮方向依存性‐ (2011)
  • Author(s): 伊東裕,丹羽政文,田中久暁,黒田新一,本杉友佳里,鈴木丈夫,大成誠一郎,田仲由喜夫,平松孝章,矢持秀起,齋藤軍治
  • Organizer: 日本物理学会2011年秋季大会
  • Place of Presentation: 富山大学 (富山市)
  • Year and Date: 20110921-24
• [Presentation] 拡張ハバードモデルにおけるβ型有機超伝導体の一軸性圧縮効果 (2010)
  • Author(s): 本杉由香里,鈴木丈夫,大成誠一郎,丹羽政文,伊東裕,田仲由喜夫
  • Organizer: 日本物理学会2010年秋季大会
  • Place of Presentation: 大阪府立大学 (堺市)
  • Year and Date: 20100923-26
• [Presentation] Uniaxial Compression effect on the Superconductivity of .-(BEDT-TTF)_2I_3 (2010)
  • Author(s): M. Niwa, H. Ito, T. Suzuki, Y. Motosugi, S. Onari, Y. Tanaka, T. Hiramatsu, H. Yamochi, and G. Saito
  • Organizer: Inter- national Conference on Science and Technology of Synthetic Metals (ICSM 2010)Inter- national Conference on Science and Technology of Synthetic Metals (ICSM 2010)
  • Place of Presentation: 京都国際会議場 (京都市)
  • Year and Date: 20100704-09
• [Presentation] Uniaxial Pressure Effect on Organic Superconductors in the Extended Hubbard Model (2010)
  • Author(s): Y. Motosugi, T. Suzuki, S. Onari, M. Niwa, T. Ishihara, H. Ito, and Y. Tanaka
  • Organizer: International Conference on Science and Technology of Synthetic Metals (ICSM 2010)
  • Place of Presentation: 京都国際会議場 (京都市)
  • Year and Date: 20100704-09
• [Remarks]
  • URL: http://www.nuap.nagoya-u.ac.jp/~kurodalab/ito.html