| Project/Area Number |
08640484
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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 |
物性一般(含基礎論)
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| Research Institution | Mie University |
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Principal Investigator |
SANO Kazuhiro Mie University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (40201537)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1998: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1997: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1996: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | High-Tc Superconductivity / Correlated Electron Systems / d-p model / Numerical Diagonalization |
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| Research Abstract |
HEAD INVESTIGATOR REGISTERED NUMBER 40201537 NAME Kazuhiro, Sano Department of Physics Engineering, Mie University Assistant Professor
Toward the clarification of the mechanism of the high temperature superconductivity, we investigate the one-dimensional d-p model by the numerical diagonalization method. The model contains electron hopping between copper (d-) site and oxygen (p-) site and repulsive Coulomb interaction on both sites. In addition, it contains the nearest-neighbor-p interaction and the hopping tpp between the nearest-neighbor p sites. It is known as a good target for investigating the possible mechanism of the high-Tc superconductivity.
By calculating the paring correlation functions and the critical exponent based on the Luttinger liquid relations, we analyzed the superconducting state induced by the effect of the large repulsion Ud at the d-site in cooperation with the transfer energy tpp. We have found that the superconducting correlation is dominant in the proximity of the parameter region where the renormalized band becomes flat. The behavior of various types of the paring correlation functions suggests that the singlet paring between the nearest neighbor p sites is the most relevant to the superconducting state.
We have also found that the low energy physics of the d-p model is well described by the t-J model. The narrowing of the effective bandwidth leads to the enhancement of the value of the effective superexchange interaction over the effective transfer J/t. It may originate the superconductivity in case of the d-p model as well as the enhancement of J/t causes the superconductivity in the case of the t-J model.
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