| Project/Area Number |
15K05167
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Condensed matter physics II
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| Research Institution | Nagoya University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
伊藤 正行 名古屋大学, 理学研究科, 教授 (90176363)
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| Project Period (FY) |
2015-04-01 – 2018-03-31
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| Project Status |
Completed (Fiscal Year 2017)
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| Budget Amount *help |
¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2017: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2015: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
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| Keywords | ネマチック状態 / 鉄系超伝導体 / 軌道秩序 / 核磁気共鳴 / 電場勾配 / ナイトシフト / 磁気ゆらぎ / 電荷ゆらぎ / 電子ネマチック状態 / 斜方晶歪 / 電気四重極周波数 / 電荷分布 / 強相関電子系 / 超伝導 / X線回折 / 中性子散乱 / 局所対称性の破れ / 鉄面内異方性 |
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| Outline of Final Research Achievements |
Nematic fluctuation was investigated from 75As nuclear magnetic resonance for the iron based superconductors Ba(Fe1-xCox)2As2, NaFeAs, and LiFeAs. We found that the electric nematic fluctuation obtained from Raman scattering can be monitored from the temperature and x dependence of the in-plane anisotropy (eta) of the electric field gradient at the As nuclear position. The eta for all samples shows Curie-Weiss type temperature dependence, where the fitting parameters, C_eta and T_eta, which correspond to Curie constant and the Weiss temperatures, respectively, systematically have x-dependences. The T_eta’s show roughly ~ Ts-50 (K) in x <0.05 where the nematic order emerges (Ts is nematic ordered temperature). Similarly with the result of Raman scattering, the T_eta becomes zero with x~0.055. At x>0.055, we found that the T_eta’s become negative, suggesting the existence of antiferro-type orbital fluctuation.
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