Topological invariant in chiral superconductors

• Project/Area Number: 25800183
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: Hokkaido University
• Principal Investigator: Nobukane Hiroyoshi 北海道大学, 理学(系)研究科(研究院), 助教 (60550663)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000); Fiscal Year 2015: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2014: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2013: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: カイラル超伝導 / 量子アノマリー / チャーン不変量 / トポロジカル量子輸送現象 / トポロジカル量子現象 / トポロジカル不変量 / メゾスコピック系

Outline of Final Research Achievements

We report the topological invariant in Sr2RuO4 nanoscale single crystals by measuring the electric transport properties. We observed the parity violation of current-voltage curves due to the excitation of the Majorana-Wyle fermions along the one-dimensional chiral edge current of single domain Sr2RuO4. In the absence of an external magnetic field, the two-dimensional surface transport in Sr2RuO4 thin films exhibited a fractional quantum Hall conductance in the superconducting state. The fractional magnetic-field-induced electric polarization was observed under zero bias current as the three-dimensional interlayer conduction. The　fractional axion angle θ=π/6 is determined by observing the topological magneto-electric effect in Sr2RuO4 nanocrystals.

Research Products

• [Journal Article] STM spectroscopy on deuterated kappa-(ET-d[3,3])2Cu[N(CN)2]Br (2015)
  • Author(s): Y. Oka, H. Nobukane, N. Matsunaga, K. Nomura, K. Katono, K. Ichimura, A. Kawamoto
  • Journal Title: Physica B Volume: 460 Pages: 93-95
  • DOI: 10.1016/j.physb.2014.11.047
  • Peer Reviewed / Open Access
• [Journal Article] Tunneling Spectroscopy in Organic Superconductor κ-(BEDT-TTF-d[3,3])2Cu[N(CN)2]Br (2015)
  • Author(s): Y. Oka, H. Nobukane, N. Matsunaga, K. Nomura, K. Katono, K. Ichimura and A. Kawamoto
  • Journal Title: J. Phys. Soc. Japan Volume: 84 Issue: 6 Pages: 064713-064713
  • DOI: 10.7566/jpsj.84.064713
  • NAID: 210000133595
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Topological electromagnetic response in the chiral superconductors Sr2RuO4 (2014)
  • Author(s): Hiroyoshi Nobukane, Toyoki Matsuyama, and Satoshi Tanda
  • Journal Title: Physica B Volume: 460 Pages: 168-170
  • DOI: 10.1016/j.physb.2014.11.062
  • Peer Reviewed
• [Journal Article] Topological transport in Sr2RuO4 (2014)
  • Author(s): H. Nobukane, T. Matsuyama, S. Tanda
  • Journal Title: Topologica Volume: 3
  • Peer Reviewed
• [Journal Article] Tunneling Spectroscopy on λ-(BETS)2GaCl4 (2014)
  • Author(s): Y. Oka, H. Nobukane, N. Matsunaga, K. Nomura, F. Sultana, A. Kobayashi, H. Kobayashi
  • Journal Title: Topologica Volume: 3
  • Peer Reviewed
• [Presentation] κ-(BEDT-TTF)2Cu[N(CN)2]Brにおける異方的超伝導ギャップ:STM分光 (2016)
  • Author(s): 生松倫太郎
  • Organizer: 日本物理学会 第71回年次大会
  • Place of Presentation: 東北学院大学（宮城県、仙台市）
  • Year and Date: 2016-03-21
• [Presentation] Sr2RuO4の量子アノマリー現象 (2015)
  • Author(s): 延兼 啓純
  • Organizer: トポロジーが紡ぐ物質科学のフロンティア 第1回領域研究会
  • Place of Presentation: 京都大学（京都府、京都市）
  • Year and Date: 2015-12-11
• [Presentation] κ-(ET)2Xナノ単結晶薄膜における電子輸送測定 (2015)
  • Author(s): 山崎隆俊
  • Organizer: 日本物理学会 2015年秋季大会
  • Place of Presentation: 関西大学（大阪府、吹田市）
  • Year and Date: 2015-09-17
• [Presentation] Chern structure in Sr2RuO4 thin films (2015)
  • Author(s): H. Nobukane
  • Organizer: The 11th Conference on Materials and Mechanisms of Superconductivity 2015 (M2S2015)
  • Place of Presentation: Geneva(Switzerland)
  • Year and Date: 2015-08-27
  • Int'l Joint Research
• [Presentation] Chern structure in Sr2RuO4 thin films (2015)
  • Author(s): H. Nobukane, T. Matsuyama and S. Tanda
  • Organizer: The 11th International Conference on Materials and Mechanisms of Superconductivity 2015
  • Place of Presentation: Geneva International Conference Center, Switzerland
  • Year and Date: 2015-08-23 – 2015-08-28
• [Presentation] Sr2RuO4におけるチャーン不変量の観測 (2015)
  • Author(s): 延兼啓純、松山豊樹、丹田聡
  • Organizer: 日本物理学会 第70回年次大会
  • Place of Presentation: 早稲田大， 新宿区
  • Year and Date: 2015-03-21 – 2015-03-24
• [Presentation] Topological electromagnetic response in the chiral superconductors Sr2RuO4 (2014)
  • Author(s): H. Nobukane, T. Matsuyama and S. Tanda
  • Organizer: International School and Workshop on Electronic Crystals ECRYSCargese-2014
  • Place of Presentation: The Scientific Institute, France
  • Year and Date: 2014-08-11 – 2014-08-23
• [Presentation] STM spectroscopy on deuterated κ-(ET-d[3,3])2Cu[N(Cn)2]Br (2014)
  • Author(s): Y. Oka, H. Nobukane, N. Matsunaga, K. Nomura, K. Katono, K. Ichimura, A. Kawamoto
  • Organizer: International School and Workshop on Electronic Crystals ECRYS-2014
  • Place of Presentation: The Scientific Institute, France
  • Year and Date: 2014-08-11 – 2014-08-23
• [Presentation] 有機超伝導体κ-(ET)2Cu[N(CN)2]Brの角度分解STM分光 (2014)
  • Author(s): 岡雄基，延兼啓純，松永悟明，野村一成，河本充司, 上遠野一広，市村晃一
  • Organizer: 日本物理学会 第69回年次大会
  • Place of Presentation: 東海大学，平塚市
• [Presentation] Majorana edge transport in Sr2RuO4 (2013)
  • Author(s): H. Nobukane, T. Matsuyama, S. Tanda
  • Organizer: FIRST-QS2C Workshop on "Emergent Phenomena of Correlated Materials"
  • Place of Presentation: Shinagawa Intercity Hall, Tokyo
• [Presentation] Topological transport in Sr2RuO4 (2013)
  • Author(s): H. Nobukane, T. Matsuyama and S. Tanda
  • Organizer: International Workshop on Phase Transition, Critical Phenomena and Related Topics in Complex Networks
  • Place of Presentation: Hokkaido University, Sapporo
• [Presentation] Tunneling Spectroscopy on λ-(BETS)2GaCl4 (2013)
  • Author(s): Y. Oka, H. Nobukane, N. Matsunaga, K. Nomura, F. Sultana, A. Kobayashi and H. Kobayashi
  • Organizer: International Workshop on Phase Transition, Critical Phenomena and Related Topics in Complex Networks
  • Place of Presentation: Hokkaido University, Sapporo
• [Presentation] 有機超伝導体β"-(BEDT-TTF)4[(H3O)Ga(C2O4)3]・C6H5NO2のSTM分光 (2013)
  • Author(s): 高橋周，岡雄基，延兼啓純，松永悟明，野村一成，関春海，井原慶彦，河本充司
  • Organizer: 日本物理学会 2013年秋季大会
  • Place of Presentation: 徳島大学，徳島市
• [Remarks] 北海道大学理学研究院物理学部門低次元電子物性研究室ホームページ内
  • URL: http://exp-ap.eng.hokudai.ac.jp/~nobukane/wiki/index.php
• [Remarks] 北海道大学理学研究院物理学部門低次元電子物性研究室ホームページ内
  • URL: http://exp-ap.eng.hokudai.ac.jp/~nobukane/wiki/index.php