Small-number vortex state in mesoscopic high-Tc superconductors
| Project/Area Number |
16H04022
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Condensed matter physics II
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| Research Institution | National Institute for Materials Science |
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Principal Investigator |
Ooi Shuuichi 国立研究開発法人物質・材料研究機構, 機能性材料研究拠点, 主任研究員 (10354292)
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| Research Collaborator |
Mochiku Takashi
Tachiki Minoru
Arisawa Shunichi
Wang Hua-bing
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥17,940,000 (Direct Cost: ¥13,800,000、Indirect Cost: ¥4,140,000)
Fiscal Year 2018: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2017: ¥7,670,000 (Direct Cost: ¥5,900,000、Indirect Cost: ¥1,770,000)
Fiscal Year 2016: ¥8,580,000 (Direct Cost: ¥6,600,000、Indirect Cost: ¥1,980,000)
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| Keywords | 高温超伝導 / 渦糸 / メゾスコピック / 正多角形 / 超伝導材料・素子 / 低温物性 / 渦糸状態 |
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| Outline of Final Research Achievements |
High-Tc superconductors exhibit unique vortex states, e.g., vortex solid to liquid phase transition and vortex glass transition, because of their large thermal fluctuation and highly-anisotropic layered structure. To investigate how the vortex states are modified by reducing the lateral size of crystals, we have performed c-axis transport measurements in a wide range of temperature and magnetic field using various shapes (equilateral triangle, square, pentagon, hexagon, etc.) and dimensions (from sub to 10 micron) of samples fabricated by a focused ion beam. As a result, we succeeded to explore the vortex state down to 5K and to reveal vortex states even in a sub-micron sample. Furthermore, in comparison with numerical simulations of the configuration of vortices in various shapes, we could understand the reason of the oscillating behavior of the melting transition temperature, which is specific in mesoscopic samples.
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| Academic Significance and Societal Importance of the Research Achievements |
互いに相互作用する多粒子から成る系の自己組織化とそのエネルギー的な安定性は、解析的な解が得難いがゆえに、様々な物理系において観測がなされている他、数値計算による解明が進んでいる。超伝導渦糸系でも渦糸殻構造などに注目した同様の研究が行われた。今回、メゾスコピックサイズの高温超伝導体を用いることで、自己組織化した渦糸結晶状態の融解転移を観測でき、その転移温度からエネルギー的な安定性を調べることが可能であることを示した。また、サブミクロンサイズまでの微小化を進める上で得られた微細加工の技術的知見や微小試料中の渦糸物性の理解は、未来の高温超伝導単結晶デバイス応用につながることが期待される。
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Report
(4 results)
Research Products
(21 results)
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[Presentation] Anomalous Enhancement of Critical Current Density due to Novel Planar Defects in CaKFe4As42018
Author(s)
T. Tamegai, A. Takahashi, S. Pyon, N. Ito, S. Ishida, A. Iyo, H. Eisaki, M. Imai, H. Abe, T. Terashima, S. Ooi, A. Ichinose
Organizer
M2S-2018 conference
Related Report
Int'l Joint Research
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