Confirmation of anomalous superconductivity in subnano-scale particles

• Project/Area Number: 24654099
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Single-year Grants
• Research Field: Condensed matter physics II
• Research Institution: The University of Tokyo
• Principal Investigator: HASEGAWA Tetsuya 東京大学, 理学(系)研究科(研究院), 教授 (10189532)
• Project Period (FY): 2012-04-01 – 2014-03-31
• Project Status: Completed (Fiscal Year 2013)
• Budget Amount: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2013: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2012: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 高温超伝導 / ナノ粒子 / 局所磁気特性 / SQUID顕微鏡 / 超伝導 / サブナノ粒子 / ジョセフソン接合 / 量子化磁束

Research Abstract

Local magnetic properties of YBaCuO superconducting nanoparticles were investigated by scanning Superconducting QUntum Interference Devise (SQUID) microscopy, SSM. The SSM image obtained at 3 K clearly showed magnetic signals. It is unlikely that quantized flux was formed inside a nanoparticle, because the size of nanoparticles is equivalent to the coherence length of YBaCuO. Indeed, the amount of magnetic flux observed by SSM was different from that of quantized flux. Thus, the observed magnetic signal is thought to originate from magnetic flux trapped inside the assembly of subnano-particles, which are connected with each other through Josephson junctions. The magnetic signal disappeared below bulk Tc.

Research Products

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  • URL: http://www.chem.s.u-tokyo.ac.jp/users/sschem/