Dynamics of Josephson vortex induced in mesoscopic high-Tc superconductors and the artificial control

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K05256
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 29010:Applied physical properties-related
• Research Institution: National Institute for Materials Science
• Principal Investigator: OOI Shuuichi 国立研究開発法人物質・材料研究機構, 国際ナノアーキテクトニクス研究拠点, 主任研究員 (10354292)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 固有ジョセフソン接合 / ジョセフソン磁束 / パンケーキ磁束 / 磁気量子振動 / 磁気光学イメージング

Outline of Final Research Achievements

The copper oxide high-Tc superconductor Bi2212 single crystal incorporates an atomic layer Josephson junction (intrinsic Josephson junction). Since junction resistance is considered to be related to the dynamics of Josephson vortex induced by pancake vortex penetration, we measured the in-plane magnetoresistance of micro Bi2212 single crystals fabricated in various shapes to obtain static and dynamic information on the vortex arrangement and respective penetration processes. We also studied the magnetic quantum oscillation phenomenon that appears when a single hole is introduced. Furthermore, along with the study of sample fabrication methods, we also worked on visualization and control of vortex states by magneto-optical imaging and obtained certain results, such as showing the possibility of vortex control in Bi2212 by vortices in different superconductors.

Free Research Field

超伝導

Academic Significance and Societal Importance of the Research Achievements

狭い領域に閉じ込められた相互作用する粒子系の普遍的性質を調べる上で、微小Bi2212におけるパンケーキ磁束およびジョセフソン磁束系は、固有ジョセフソン接合の電気特性を通してその状態を知ることができる独特な研究対象の一つである。様々な形状に加工されたBi2212単結晶の固有ジョセフソン接合特性を通して、2種類の磁束量子によって生み出される静的・動的な磁束の振る舞いについて理解を深めることができた。さらに、直接磁束状態を可視化する試みにより、磁束量子制御につながる成果を得ることができた。