2022 Fiscal Year Final Research Report
Unified elucidation of the genuine electronic state and the mechanism of superconductivity in cuprates with different coordination numbers
| Project/Area Number |
19H01841
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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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| Review Section |
Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
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| Research Institution | Sophia University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
藤田 全基 東北大学, 金属材料研究所, 教授 (20303894)
木村 宏之 東北大学, 多元物質科学研究所, 教授 (50312658)
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Keywords | 高温超伝導 / T'型銅酸化物 / 無限層銅酸化物 / T*型銅酸化物 / ミュオンスピン緩和 / X線吸収微細構造 / 中性子回折 / 放射光X線回折 |
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| Outline of Final Research Achievements |
Transport properties, muSR, synchrotron X-ray and neutron diffraction measurements were performed on T'-type, infinite-layer, T*-type cuprates with controlled oxygen content. It was clarified that the T'-cuprates become metallic by electron doping upon reduction, that the bulk structure along with the oxygen removal are related to the appearance of superconductivity in the T'-cuprates, and that the superconductivity is observed down to the low hole-concentration regime in the T*-cuprates. The electronic structure model is likely to provide a unified understanding of the electronic structure of the cuprates with different coordination numbers including the T structure.
In the T'-cuprates, the existence of multiple carriers originating from antiferromagnetic fluctuations in the bulk superconducting samples suggests that the superconductivity and antiferromagnetic fluctuations are closely related with each other.
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| Free Research Field |
超伝導物性学
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| Academic Significance and Societal Importance of the Research Achievements |
配位数が4，5，6と異なる銅酸化物の電子状態を電子構造モデルで統一的に理解できる可能性があることを示した点は，様々なエキゾチック物性を示す他の遷移金属酸化物の電子状態の理解に役立つものなので学術的に意義深い．
本研究は，配位数を制御することで絶縁体を超伝導体に変えることができる可能性を示したものである．今後は，従来の元素置換を含めた多様な方法で新規高温超伝導体の創製の研究が発展するだろう．
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