Anomalous Metalic State in Strongly Correlated Systems

强相关系统中的反常金属态

基本信息

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

项目摘要

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.

自从发现高温超导体以来，低维强相关系统中的电子激发引起了人们的广泛关注。在一维（1D）系统中，已知会发生自旋电荷分离，并且电子的自旋和电荷自由度服从不同的动力学。自旋和电荷的基本激发分别称为自旋子和完整子。二维（2D）系统中自旋和电荷自由度的性质是高温超导体研究的中心问题之一。角分辨光电子能谱 (ARPES) 的最新进展提供了测试强相关系统理论的机会。我们通过使用解析和计算方法研究了强相关低维系统中的单粒子、自旋和电荷激发。数值方法。半填充时的单粒子光谱与一维铜酸盐SrCuO_2中的最新角分辨光电子发射光谱一致，并且与二维一维Sr_2CuO_2Cl_2中的角分辨光电子发射光谱形成强烈对比。在二维中，这些激发光谱的行为强烈依赖于电子浓度。远离半填充，单粒子光谱包括费米液体中预期的自旋和电荷激发。另一方面，接近半填充时，谱与一维中的谱非常相似，表明电荷和自旋自由度服从不同的动力学。我们的研究为新的固体量子理论提供了基础。电子的内部自由度。