Study of Quantum Vortex States in Spin-triplet Chiral p-wave Superconductor

• Project/Area Number: 15K17708
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: Keio University (2016); Tokyo University of Science (2015)
• Principal Investigator: NAGO YUSUKE 慶應義塾大学, 理工学部(矢上), 助教 (50623435)
• Research Collaborator: SAKUMA Daisuke ; SHINOZAKI Tomoya ; SATO Taichi
• Project Period (FY): 2015-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2016: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2015: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
• Keywords: カイラル超伝導 / 磁束量子渦 / メゾスコピック系 / 超伝導量子干渉計 / 低温物性 / 超伝導

Outline of Final Research Achievements

We developed magnetization measurement devices composed of micro dc-SQUIDs and Sr2RuO4(SRO) microplates for clarification of novel quantum vortex states attributable to spin-triplet chiral p-wave superconductivity, and obtained the experimental results as follows.
1.Two distinct signals of the vortices implying influence of chiral superconductivity were obtained. 2. In the magnetization measurements under the in-plane magnetic field, the vortex signal implying a half-quantum vortex was detected. 3. In the magnetization measurements of SRO-Ru eutectic microplates, spatial distribution change of induced magnetic flux due to the superconducting transition of Ru was observed. However, spontaneous nucleation of vortex attributable to the phase competition between s-wave and chiral p-wave superconductivities was not observed.

Research Products

• [Journal Article] Evolution of supercurrent path in Nb/Ru/Sr2RuO4 dc-SQUIDs (2016)
  • Author(s): Y. Nago, R. Ishiguro, T. Sakurai, M. Yakabe, T. Nakamura, S. Yonezawa, S. Kashiwaya, H. Takayanagi, Y. Maeno
  • Journal Title: Physical Review B Volume: 94 Issue: 5
  • DOI: 10.1103/physrevb.94.054501
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Development of Magnetization Measurement Devices Using Micro-dc-SQUIDs and a Sr2RuO4 Microplate (2016)
  • Author(s): Y. Nago, T. Shinozaki, S. Tsuchiya, R. Ishiguro, H. Kashiwaya, S. Kashiwaya, S. Nomura, K. Kono, H. Takayanagi, Y. Maeno
  • Journal Title: Journal of Low Temperature Physics Volume: 183 Issue: 3-4 Pages: 292-299
  • DOI: 10.1007/s10909-016-1530-z
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Development of a Two-Dimensional Micro-SQUID Array for Investigation of Magnetization Spatial Distribution (2016)
  • Author(s): Daisuke Sakuma, Tomoya Shinozaki, Yusuke Nago, Ryosuke Ishiguro, Satoshi Kashiwaya, Shintaro Nomura, Kimitoshi Kono, Hideaki Takayanagi
  • Journal Title: Journal of Low Temperature Physics Volume: 183 Issue: 3-4 Pages: 300-306
  • DOI: 10.1007/s10909-016-1556-2
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Presentation] Sr2RuO4-Ru共晶における磁束量子渦状態 (2017)
  • Author(s): 佐久間大輔，○永合祐輔、石黒亮輔，柏谷聡，野村晋太郎，河野公俊，前野悦輝，高柳英明
  • Organizer: 日本物理学会第72年次大会
  • Place of Presentation: 大阪大学豊中キャンパス(大阪府豊中市)
• [Presentation] Sr2RuO4-Ru共晶中に誘起される磁束量子渦の観測II (2016)
  • Author(s): 佐久間大輔，篠崎智也，永合祐輔，石黒亮輔，柏谷聡，野村晋太郎，河野公俊，前野悦輝，高柳英明
  • Organizer: 日本物理学会第71回年次大会
  • Place of Presentation: 東北学院大学 泉キャンパス
  • Year and Date: 2016-03-19
• [Presentation] マイクロdc-SQUIDを用いたメゾスコピック超伝導Sr2RuO4における半整数磁束量子渦の探索 (2016)
  • Author(s): 佐藤太一，濱崎拓也，永合祐輔，篠崎智也，石黒亮輔，柏谷聡，野村晋太郎，河野公俊，前野悦輝，高柳英明
  • Organizer: 日本物理学会第71回年次大会
  • Place of Presentation: 東北学院大学 泉キャンパス
  • Year and Date: 2016-03-19
• [Presentation] マイクロSQUIDを用いた超伝導Sr2RuO4に誘起される磁束量子渦の観測 (2016)
  • Author(s): 永合祐輔，佐藤太一，篠崎智也，佐久間大輔, 石黒亮輔，柏谷聡，柏谷裕美，野村晋太郎，河野公俊，前野悦輝，高柳英明
  • Organizer: 日本物理学会2016年秋季大会
  • Place of Presentation: 金沢大学角間キャンパス(石川県金沢市)
• [Presentation] Observation of quantum vortex state in Sr2RuO4 using micro-SQUIDs (2016)
  • Author(s): 永合祐輔、篠崎智也、佐藤太一，石黒亮輔，柏谷聡，柏谷裕美、野村晋太郎，河野公俊，前野悦輝，高柳英明
  • Organizer: 第2回TMS領域研究会(TMS2016)
  • Place of Presentation: 東北大学片平キャンパスさくらホール(宮城県仙台市)
• [Presentation] Observation of quantum vortex state in Sr2RuO4-Ru eutectic using micro-SQUIDs (2016)
  • Author(s): 佐久間大輔，○永合祐輔，石黒亮輔，柏谷聡，柏谷裕美、野村晋太郎，河野公俊，前野悦輝，高柳英明
  • Organizer: 第2回TMS領域研究会(TMS2016)
  • Place of Presentation: 東北大学片平キャンパスさくらホール(宮城県仙台市)
• [Presentation] Sr2RuO4-Ru共晶中に誘起される磁束量子渦の観測 (2015)
  • Author(s): 佐久間大輔，篠崎智也，永合祐輔，石黒亮輔，柏谷聡，野村晋太郎，河野公俊，前野悦輝，高柳英明
  • Organizer: 日本物理学会2014年秋季大会
  • Place of Presentation: 関西大学 千里山キャンパス
  • Year and Date: 2015-09-16
• [Presentation] 電子ビーム描画装置を用いてSr2RuO4-Ru共晶中に作製したNb/Ru/Sr2RuO4微小接合を持つdc-SQUIDの開発 (2015)
  • Author(s): 谷下 智紀、永合 祐輔、石黒 亮輔、渡辺 英一郎、大里 啓孝、津谷 大樹、柏谷 聡、柏谷 裕美、野村 晋太郎、河野 公俊、Muhammad Shahbaz ANWAR、前野 悦輝、高柳 英明
  • Organizer: 第76回応用物理学会秋季学術講演会
  • Place of Presentation: 名古屋国際会議場（
  • Year and Date: 2015-09-13
• [Presentation] Development of Magnetization Measurement Device using Micro-SQUIDs and a Mesoscopic Sr2RuO4 Superconductor (2015)
  • Author(s): Y. Nago, T. Shinozaki, T. Sato, D. Sakuma, R. Ishiguro, H. Kashiwaya, S. Kashiwaya, S. Nomura, K. Kono, Y. Maeno , and H. Takayanagi
  • Organizer: 2015 International Symposium on Quantum Fluids and Solids(QFS2015)
  • Place of Presentation: Conference Event Center, Niagara Falls, NY USA
  • Year and Date: 2015-08-10
  • Int'l Joint Research
• [Presentation] Development of Micro-SQUID Array for Simultaneous Measurements of Magnetization Spatial Distribution (2015)
  • Author(s): D. Sakuma, T. Shinozaki, Y. Nago, R. Ishiguro, S. Kashiwaya, S. Nomura, K. Kono, Y. Maeno, and H. Takayanagi
  • Organizer: 2015 International Symposium on Quantum Fluids and Solids(QFS2015)
  • Place of Presentation: Conference Event Center, Niagara Falls, NY USA
  • Year and Date: 2015-08-10
  • Int'l Joint Research