2012 Fiscal Year Final Research Report
Study of twp-gap problem of cuprate superconductors using variation method and BdG equation
| Project/Area Number |
22540359
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | Tohoku University |
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Principal Investigator |
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| Co-Investigator(Renkei-kenkyūsha) |
OGATA Masao 東京大学, 理学系研究科, 教授 (60185501)
TSUCHIURA Hiroki 東北大学, 工学研究科, 准教授 (30374961)
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| Project Period (FY) |
2010 – 2012
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| Keywords | 超伝導 / 銅酸化物 / 擬ギャップ / 変分法 / クロスオーバー / モット絶縁体 |
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| Research Abstract |
With cuprates in mind, we systematically studied properties of pseudogap and d-wave superconductivity, which are keys to clarify the mechanism of high-Tc cuprates. We mainly applied a variational Monte Carlo method to the Hubbard model. Near half filling, as the interaction strength is increased, every state exhibits, at approximately the band width, a crossover closely related to the Mott transition at half filling. The weakly correlated regime corresponds to a Fermi liquid (BCS superconducting) phase, and the strongly correlate regime to a doped Mott insulating phase, in which physics is dominated by singly occupied sites and the doublon-holon binding effect. Properties of cuprates are consistent to those in the latter regime.
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