Anomalous Metalic State in Strongly Correlated Systems

强相关系统中的反常金属态

• 批准号: 07044078
• 负责人: MAEKAWA Sadamichi
• 金额: $ 4.35万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07044078/
• 关键词: electron correlation; spin charge separation; high Tc superconductivity; Mott transition; anomalous metal; heavy electron; one-dimensional metal; spin fluctuation; gause field; f・電子系; d・電子系; 金属・絶縁体転移; フェルミ流体; 朝永・ラッティンジャー流体

Electronic excitations in low-dimensional strongly correlated systems have attracted considerable attention since the discocvery of high temperature superconductors. In the one-dimensional (1D) systems, it is known that the spin-charge separation occurs and the spin and charge degress of freedom of electrons obey the different dynamics. The elementary excitations of spin and charge are called spinons and holons, respectively. The nature of spin and charge degrees of freedom in the two-dimensional (2D) systems is one of the central issues in the study of high temperature superconductors. Recent advances in angle-resolved photoemission spectroscopy (ARPES) offers an opportunity of testing the theory of the strongly correlated systems.We have studied the single-particle, spin and charge excitations in strongly correlated low-dimensional systems by using the analytical as well as numerical methods. The single-particle spectrum at half-filling is in accord with the recent angle-resolved photoemission spectrum in the 1D cuprate SrCuO_2 and is in strong contrast with that in the 2D one Sr_2CuO_2Cl_2. In 2D,the behaviors of these excitation spectra are strongly dependent on electron concentration. Far away from half-filling, the single-particle spectrum includes both spin and charge excitations as expected in a Fermi liquid. On the other hand, near half-filling, the apectra are rather similar to those in 1D,indicating that the charge and spin degrees of freedom obey the different dynamics.Our study offers a basis of the new quantum theory of solids which starts with the internal degrees of freedom of electrons.

自从高温超导体的辨别力以来，低维系统中的电子激发引起了人们的关注。在一维（1D）系统中，众所周知，旋转电荷分离发生，电子自由度的自旋和电荷效果遵守不同的动力学。旋转和电荷的基本激发分别称为旋子和霍姆。二维（2D）系统中自旋和电荷自由度的性质是研究高温超导体研究的中心问题之一。角度分辨光发射光谱（ARPES）的最新进展提供了测试强相关系统理论的机会。我们研究了通过分析和数值方法和数值方法研究了强相关的低维系统中的单粒子，自旋和电荷激发。半填充时的单粒子频谱与1d Cuprate SRCUO_2中的最新角度分辨光发射光谱一致，并且与2d One SR_2CUO_2CL_2中的相对鲜明对比。在2D中，这些激发光谱的行为很大程度上取决于电子浓度。单粒子频谱远离半填充，包括在费米液体中预期的自旋和电荷激发。另一方面，接近半填充的山顶与1d中的竞技相当相似，表明自由度的电荷和自旋程度遵守了不同的动力学。

项目成果

S.Fujimoto: "Competition between the Mott Transition and the Anderson Localization in 1D Disordered Interacting Electron Systems" Phys.Rev.B. 54. 11018-11021 (1996)

S.Fujimoto：“一维无序相互作用电子系统中莫特跃迁与安德森局域化之间的竞争”Phys.Rev.B。

E.Dagotto: "Surprises on the Way from 1D to 2D Quantum Magnets : the Novel Ladder Materials" Science. 271. 618-623 (1996)

E.Dagoto：“从 1D 到 2D 量子磁体的过程中的惊喜：新型阶梯材料”科学。

K.Ueda: "Plaquette Resonating-Valence-Bond Ground State of CaV_4O_9" Phys.Rev.Lett.76. 1932-1935 (1996)

K.Ueda：“CaV_4O_9 的板共振价键基态”Phys.Rev.Lett.76。

E.Dagotto: "One-dimensional systems display new depths" Physics World, (1996)

E.Dagoto：“一维系统显示新的深度”物理世界，（1996）

D.Yoshioka: "Edge State Transport in Separately Contacted Double-Layer Quantum Hall Systems" Phys.Rev.B. 53. R16168-R16171 (1996)

D.Yoshioka：“分离接触双层量子霍尔系统中的边缘态传输”Phys.Rev.B。