2013 Fiscal Year Final Research Report
Pairing mechanism and symmetry of iron-based high-temperature superconductivity
| Project/Area Number |
23540443
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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 |
Mathematical physics/Fundamental condensed matter physics
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| Research Institution | Niigata University |
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Principal Investigator |
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| Co-Investigator(Renkei-kenkyūsha) |
SANO Kazuhiro 三重大学, 工学部, 教授 (40201537)
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| Project Period (FY) |
2011 – 2013
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| Keywords | 鉄系超伝導体 / 高温超伝導発現機構 / 電子相関 / 電子格子結合 / 磁気揺らぎ / 軌道揺らぎ / d-p模型 / 動的平均場理論 |
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| Research Abstract |
Strong correlation effects in iron-based superconductors have been investigated by using the dynamical mean-field theory with the Eliashberg equation. The renormalization factor exhibits significant orbital dependence as observed in recent ARPES experiments. The magnetic and orbital orders are largely suppressed as compared with those from the RPA due to local correlation effects. Remarkably, the s++-pairing phase due to the orbital fluctuation is largely expanded relative to the RPA result, while the s+--pairing phase due to the magnetic fluctuation is reduced. The effect of the intersite Coulomb interaction between Fe d and As p electrons has also been studied and is found to enhance the ferro-orbital (FO) fluctuation responsible for the C66 elastic softening. The FO fluctuation and the antiferromagnetic fluctuation enhanced due to the onsite d-d Coulomb interaction cooperatively enhance Tc of s+--wave superconductivity without any competition by virtue of the q-space segregation.
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Research Products
(63 results)
