Spin Density and Quantum Fluctuations in Quasi-One-Dimensional Conductors

准一维导体中的自旋密度和量子涨落

• 批准号: 05640410
• 负责人: SUZUMURA Yoshikazu
• 金额: $ 1.28万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05640410/
• 关键词: Quasi-1D Conductor; Spin Density Wave; Collective Mode; Spin Fluctuation; Phase Hamiltonian; DCNQI-Cu; Strong Correlation; Metal-Insnlator Transition; 擬一次元有機導体; DCNQI-Cu塩; 強相関電子系; アニオン格子; 金属-絶縁体; 運動量分布; DCNQI塩; 比熱; 電荷密度波; リエントラント

The role of repulsive interaction in quasi-one-dimensional organic conductors has been studied in order to examine the fluctuation of spin density in low-dimensioanl electron system. Following three subjects have been investigated. (1) The fluctuation of the commensurate spin density wave (SDW) has been examined by calculating collective modes of a Hubbard model with a quarter-filled band. The longitudinal mode shows the gap and the coexistence of the 2k_F-SDW and the 4k_F-CDW.The effect of anion lattice was examined in terms of a phase Hamiltonian. (2) A role of interchain hopping in quasi-1D organic conductors was examined by applying the phase Hamiltonian based on the bosonization to two coupled chains with the repulsive interaction of backward and forward scatterings. The competition of SDW state and superconducting state explains the phase diagram of in the quasi-1D conductors. (3) The metal-insulatortarnsition in DCNQI-Cu salts was examined by applying the slave-boson mean-field theory to the periodic Anderson model with the electron-phonon (e-p) interaction. The fact that the M-I transition is the Peierls transition in the presence of the strong correlation has been shown by calculating the reentrant transition of M-I-M,the phase diagram specific heat and magnetic susceptibility, the dimensional effect and the antiferromagnetic state. Thus we have shown the mechanism of the M-I transition.

为了研究低维电子系统中自旋密度的涨落，研究了准一维有机导体中排斥相互作用的作用。对以下三个主题进行了调查。 (1) 通过计算具有四分之一填充带的哈伯德模型的集体模式来检查相应自旋密度波（SDW）的波动。纵模显示了2k_F-SDW和4k_F-CDW的间隙和共存。根据相位哈密顿量检验了阴离子晶格的影响。 (2)通过将基于玻色化的相位哈密顿量应用于具有向后和向前散射的排斥相互作用的两个耦合链，研究了准一维有机导体中链间跳跃的作用。 SDW态与超导态的竞争解释了准一维导体中的相图。 (3) 通过将从玻色子平均场理论应用于具有电子-声子 (e-p) 相互作用的周期性安德森模型，研究了 DCNQI-Cu 盐中的金属-绝缘体转变。通过计算M-I-M的重入转变、相图比热和磁化率、尺寸效应和反铁磁态，证明了M-I转变是存在强相关性的Peierls转变。这样我们就展示了M-I转变的机制。

项目成果

Y.Suzumura: "Metal-Insulator Transition in Organic Conductor DCNQI-Cu Salt" Synthetic Metals. 70. 1083-1084 (1995)

Y.Suzumura：“有机导体 DCNQI-Cu 盐中的金属-绝缘体转变”合成金属。

Y.Ono: "Kondo Insulator and Charge Transfer Insulator in Lattice Anderson Model" J.Phys.Soc.Jp. 63(発表予定). (1994)

Y.Ono：“格子安德森模型中的近藤绝缘体和电荷转移绝缘体”J.Phys.Soc.Jp.63（待发表）。

Y.Suzumura: "Anisotropic Order Parameters for Two-Dimensional Strong Coupling Superconductors" Synthetic Metals. 71. 1635-1636 (1995)

Y.Suzumura：“二维强耦合超导体的各向异性有序参数”合成金属。

Y.Suzumura: "Heavy Electrons in DCNQI-Cu Salts" Solid State Physics (Kotai Butsuri) (in Japanese). Vol.28. 87-94 (1993)

Y.Suzumura：“DCNQI-Cu 盐中的重电子”固体物理 (Kotai Butsuri)（日语）。

N.Tanemura and Y.Suzumura: "Collective Modes and Magnetic Susceptibility of SDW State with One-Dimensional Half-filled Band" J.Phys.Soc.Jpn.Vol.64. 2158-2165 (1995)

N.Tanemura 和 Y.Suzumura：“一维半填充能带 SDW 态的集体模式和磁化率”J.Phys.Soc.Jpn.Vol.64。