Observation of a charge order by noise measurement in High-Tc superconductor

• Project/Area Number: 25400360
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: The University of Tokyo
• Principal Investigator: Fujii Takenori 東京大学, 低温センター, 助教 (80361666)
• Co-Investigator(Kenkyū-buntansha): 朝光 敦 足利工業大学, 工学部, 教授 (80311645)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000); Fiscal Year 2015: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2014: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2013: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000)
• Keywords: 鉄系超伝導体 / ネマティック / 熱起電力 / 異方性 / ノイズ測定 / 面内異方性 / ネマティック秩序 / ネルンスト効果 / ネマティック電子相 / 電荷秩序 / ネマティック相

Outline of Final Research Achievements

We investigated the in-plane anisotropy of the thermopower and electrical resistivity on detwinned single crystals of Iron based superconductor. In the case of BaFe2As2, the in-plane anisotropy of the resistivity was clearly observed far above the magnetostructural transition temperature T_AFO . While, the thermopower showed the in-plane anisotropy only below T_AFO . These results are associated with the different origin of the anisotropy above and below T_AFO . Since the thermopower does not depend on the scattering time, the anisotropy of the resistivity above T_AFO is considered to be due to the anisotropic scattering. On the other hand, the anisotropy in the thermopower below T_AFO is ascribed to the reconstructed Fermi surface.

Research Products

• [Journal Article] Measurement of the thermopower anisotropy in iron arsenide (2016)
  • Author(s): T. Fujii, T. Shirachi, and A. Asamitsu
  • Journal Title: Physica C Volume: 530 Pages: 31-34
  • DOI: 10.1016/j.physc.2016.03.007
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Unscalling Superconducting Parameters with Tc for Bi-2212 and Bi-2223: A Magnetotransport Study in the Superconductive Fluctuation Regime (2015)
  • Author(s): S. Adachi, T. Usui, Y. Ito, H. Kudo, H. Kushibiki, K. Murata, T. Watanabe, K. Kudo, T. Nishizaki, N. Kobayashi, S. Kimura, M. Fujita, K. Yamada, T. Noji, Y. Koike, T. Fujii,
  • Journal Title: J. Phys. Soc. Jpn. Volume: 84 Issue: 2 Pages: 0247061-0247066
  • DOI: 10.7566/jpsj.84.024706
  • NAID: 210000133435
  • Peer Reviewed / Open Access
• [Journal Article] Simultaneous control of thermoelectric properties in p- and n-type materials by electric double-layer gating: New design for thermoelectric device (2015)
  • Author(s): Ryohei Takayanagi, Takenori Fujii, and Atsushi Asamitsu
  • Journal Title: Applied Physics Express Volume: 8 Issue: 5 Pages: 051101-051101
  • DOI: 10.7567/apex.8.051101
  • NAID: 210000137490
  • Peer Reviewed
• [Journal Article] Control of thermoelectric properties of ZnO using electric double-layer transistor structure (2014)
  • Author(s): Ryohei Takayanagi, Takenori Fujii, and Atsushi Asamitsu
  • Journal Title: Japanese Journal of Applied Physics Volume: 53 Issue: 11 Pages: 111101-111101
  • DOI: 10.7567/jjap.53.111101
  • NAID: 210000144559
  • Peer Reviewed
• [Presentation] 鉄系超伝導体における熱起電力の面内異方性II (2016)
  • Author(s): 藤井武則
  • Organizer: 日本物理学会
  • Place of Presentation: 金沢大学
  • Year and Date: 2016-09-13
• [Presentation] 日本物理学会 (2016)
  • Author(s): 藤井武則、白地貴一、朝光敦
  • Organizer: 日本物理学会 第71回年次大会
  • Place of Presentation: 東北学院大学
  • Year and Date: 2016-03-19
• [Presentation] Anisotropy of the Thermopower in Iron Arsenide (2015)
  • Author(s): T. Fujii, T. Shirachi, A. Asamitsu
  • Organizer: 28th International Symposium on Superconductivity
  • Place of Presentation: Tokyo
  • Year and Date: 2015-11-16
  • Int'l Joint Research
• [Presentation] Ba(Fe1-xCox)2As2におけるネルンスト効果の異方性 (2014)
  • Author(s): 白地貴一，藤井武則，朝光敦
  • Organizer: 日本物理学会 2014年秋季大会
  • Place of Presentation: 中部大学
  • Year and Date: 2014-09-07 – 2014-09-10
• [Presentation] 鉄系超伝導体Ba(Fe1-xCox)2As2における熱輸送特性の異方性 (2014)
  • Author(s): 藤井武則，白地貴一，朝光敦
  • Organizer: 日本物理学会 2014年秋季大会
  • Place of Presentation: 中部大学
  • Year and Date: 2014-09-07 – 2014-09-10
• [Presentation] 鉄系超伝導体Ba(Fe1-xCox)2As2のネルンスト効果による電荷秩序の観測 (2014)
  • Author(s): 藤井武則、石井健太郎、朝光敦
  • Organizer: 日本物理学会 第69回年次大会
  • Place of Presentation: 東海大学
• [Presentation] 鉄系超伝導体Ba(Fe1-xTx)2As2 (T = Ru, Co)およびBaFe2(As1-xPx)2のネルンスト係数による電荷秩序の観測 (2013)
  • Author(s): 石井健太郎、藤井武則、朝光敦
  • Organizer: 日本物理学会 2013年秋季大会
  • Place of Presentation: 徳島大学
• [Remarks] 藤井武則のホームページ
  • URL: http://www.crc.u-tokyo.ac.jp/fujii/
• [Remarks] 東京大学低温センター年次報告 平成26年度(2014年度)
  • URL: http://www.crc.u-tokyo.ac.jp/publication/annualreport/ar2014.html
• [Remarks] 東京大学低温センター年次報告 平成25年度(2013年度)
  • URL: http://www.crc.u-tokyo.ac.jp/publication/annualreport/ar2013.html