| Project/Area Number |
09640429
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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 |
SUZUMURA Yoshikazu Department of Physics, Graduate School of Science, Nagoya University, 大学院・理学研究科, 教授 (90108449)
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| Co-Investigator(Kenkyū-buntansha) |
吉岡 英生 名古屋大学, 大学院・理学研究科, 助手 (40252225)
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| Project Period (FY) |
1997 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2000: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1999: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1998: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1997: ¥700,000 (Direct Cost: ¥700,000)
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| Keywords | commensurability / impurity / two chains / bosonization / localization / phase Hamiltonian / renormalization group / spin density ware / 相関ギャップ / 不整合 / 位相 / 電荷ギャップ / モット絶縁体 / 低次元揺らぎ / 繰り込み理論 / 閉じ込め / スピンギャップ / ベッチガード塩 / くり込み群 / 朝永-ラッティンジャー液体 / 電荷揺らぎ / スペクトル関数 / 2鎖電子系 / スピンと電荷の分離 / スピン-パイエルス系 |
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| Research Abstract |
We have studied theoretically the following system based on the bosonization in order to study a role of correlation and fluctuation in low dimensional organic conductors. (i) The transition from insulator to metal occurs under pressures in the normal state of Bechgaard salts, which exhibit the charge gap. Such a transition is determined by a ratio of the charge gap to the interchain hopping. The mechanism has been studied by use of two-coupled chains with a half-filled band, in which the one-dimensional fluctuation is treated in terms of the renormalization group method. It is demonstrated that the confinement occurs when the charge gap becomes larger than than the interchain hopping. Further the effect of the electron-filling from the commensurate state has been examined. (2) The spin density wave of organic conductors exhibits a novel transition at temperature of the 1/3 of the critical temperature. By using a phase Hamiltonian for two-coupled chains of SDW, the effect of the phase difference between chain has been investigated by use of the transfer integral method. It is shown that the competition between the commensurability energy and interchain coupling gives rise to the transition from the commensurate state to the incommensurate state. (3) The effect of impurity in two-coupled spinless chain has been studied to understand the role of interchain hopping in quasi-one-dimensional systems. It is found that the one-dimensional localization occurs when the pinning energy of impurity becomes larger than the interaction induced interchain gap. Besides the above results, we have examined the electronic state of one-dimensional electrons, collective modes of spin density wave and the impurity effect on spin Peirls system.
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