2014 Fiscal Year Final Research Report
Investigation of the symmetry of superconducting gap and the FFLO state in a novel organic superconductor with the charge disproportionation
Project/Area Number |
24540353
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Condensed matter physics II
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Research Institution | Hokkaido University |
Principal Investigator |
KAWAMOTO Atsushi 北海道大学, 理学(系)研究科(研究院), 教授 (60251691)
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Co-Investigator(Kenkyū-buntansha) |
IHARA Yoshihiko 北海道大学, 理学研究院, 講師 (80598491)
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Project Period (FY) |
2012-04-01 – 2015-03-31
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Keywords | 13C-NMR / FFLO / 超伝導 / 電荷秩序 |
Outline of Final Research Achievements |
The organic salt, beta’’-(BEDT-TTF)4[(H3O)Ga(C2O4)3]C6H5NO2 is suggested to be a novel organic superconductor mediated by charge fluctuations. In addition, the upper critical field exceed its Pauli limit was reported. We performed single crystal 13C-NMR experiments on the sample with selective site isotope substitution and found the charge separation with 0.6e and 0.13e for each. We also discussed the charge disproportionation pattern using the result of the ratio of the peak intensity. We also performed single crystal 13C-NMR experiments on the sample of Fe modification where non-magnetic Ga ions were replaced with magnetic Fe ions to investigate the influence of the magnetism of Fe ions to the superconductivity. As the results we found the negative exchange interaction from Fe ions and estimated the characteristic timescale of Fe ions dynamics under the field, suggesting the possibility of a field induced superconductivity of the Fe salt.
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Free Research Field |
物性物理学
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