| Project/Area Number |
03302017
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性
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| Research Institution | University of Tokyo |
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Principal Investigator |
KAGOSHIMA Seiichi University of Tokyo,Department of Pure and Applied Sciences,Professor, 教養学部, 教授 (30114432)
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| Co-Investigator(Kenkyū-buntansha) |
OSHIMA Kokichi Okayama University,Department of Physics,Professor, 理学部, 教授 (10114414)
TAKADA Satoshi Tsukuba University,Institute of Physics,Professor, 物理学系, 教授 (10015779)
ISHIGURO Takehiko Kyoto University,Department of Physics,Professor, 理学部, 教授 (50202982)
KAJITA Koji Toho University,Department of Physics,Professor, 理学部, 教授 (50011739)
TOYOTA Naoki Tohoku University,Institute for Materials Research,Associate Professor, 金属材料研究所, 助教授 (50124607)
KACHIDA Kazushige Okayama University,Department of Physics,Associate Professor (50025491)
SUZUMURA Yoshikazu Nagoya University,Department of Physics,Associate Professor (90108449)
FUKUYAMA Hidetoshi University of Tokyo,Department of Physics,Professor (10004441)
TOKUMOTO Madoka Electrotechnical Laboratory,Senior Researcher
TAKAHASHI Toshihiro Gakushuin University,Department of Physics,Professor
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥21,000,000 (Direct Cost: ¥21,000,000)
Fiscal Year 1992: ¥10,900,000 (Direct Cost: ¥10,900,000)
Fiscal Year 1991: ¥10,100,000 (Direct Cost: ¥10,100,000)
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| Keywords | Organic Conductor / Electron Correlation / Low Dimensional Electronic System / Spin Density Wave / Magnetoresistance / Peierls Instability / 電気伝導 / 電荷密度 / スピン密度 / 価数揺動 / 抵次元電子 |
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| Research Abstract |
The purpose of the present study is to clarify effects of the Coulomb correlation among electrons to properties of low-dimensional electronic system in organic conductors.
In (BEDT-TTF)_2KHg(SCN)_4 and its family we found a geometrical effect of the two-dimensional Fermi surface to the magnetoresistance. We found also an antiferromagnetic-like state presumably due to instability of another Fermi surface of one-dimension. The anitiferromagnetic state was found to be present at low temperatures below 8 K, under weak magnetic fields below 23 T, and at low pressures below 5 Kbar.
In TMTSF salts another geometrical effect to the magneto-resistance was found. In addition we presented answers to questions about puzzling properties of the field-induced spin density waves. The high-field limiting state was found to have the quantum number of zero.
In DCNQI salts the reentrance transition was investigated in detail. Electronic properties of this class of materials were found to be understood in terms of the Peierls transition in the pi band of DCNQI molecular stacks and the Mott transition in the d band due to copper ions.
In conclusion one can say that all factors of low-dimensionality, the electron correlation, the electron-phonon interaction, and weak three-dimensionality play essential roles in electronic properties of these materials.
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