2001 Fiscal Year Final Research Report Summary
Study on Magnetism and Suprconductivity in the Non-Fermi Liquid with Channels
| Project/Area Number |
10640339
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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 |
固体物性Ⅱ(磁性・金属・低温)
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| Research Institution | Nagoya University |
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Principal Investigator |
MATSUURA Tamifusa Nagoya University, Graduate School of Scinence,Professor, 大学院・理学研究科, 教授 (10022609)
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| Co-Investigator(Kenkyū-buntansha) |
ONO Yoshiaki Nagoya University, Graduate School of Scinence, Associate, Professor, 大学院・理学研究科, 助教授 (40221832)
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| Project Period (FY) |
1998 – 2001
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| Keywords | Fermi Liquid / Non-Fermi Liquid / Critical Exponent / Slabe Boson / Pseudo-Fermion / Heavy Electron / 1 / N-Expansion / チャンネル |
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| Research Abstract |
Main purpose of this project is to study various anomalous properties in the system with multi-freedoms. These freedoms are due to magnetic dipoles, quadrupole and octapole. In this study, we investigate effects of these freedoms.
First, using 1/N expansion method in the impurity Anderson model, we determined the exponents of the infrared divergence of the slave boson and pseudo-fermion correctly. In the single channel case however the infrared divergent terms in the slave boson and pseudo-fermion cancelled out in the physical quantities completely and the system resulted in the Fermi liquid. In the multi-channel case the anomalous terms remain and system becomes non Fermi liquid. We determined the threshold exponents.
We also investigated the Anderson lattice with use of l/N : expansion method. In the single channel case the anomalous terms associated with pseudo-particles cancel out in the physical quantities and the system becomes Fermi liquid. In the multi-channel case, the resistivity has anomalous term proportional to temperature which suggests the non-Fermi liquid.
In the second we use the above 1/N-expansion method to study the high temperature superconductors. We invesitigate pseudo-gap and obtain the phase diagram with TO, Tsg and Tc advocated by Sato'group. The origin of the pseudo-gap is due to the interplay between the spin flucuations and superconducting fluctuations. We deriverd the phase diagram theoretically.
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