Finite-temperature properties of doped antiferromagnets
Finite-temperature properties of doped antiferromagnets
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DOI：
10.1002/chin.200042249
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发表时间：
1998-03
影响因子：
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通讯作者：
J. Jaklic;P. J. Institute;Ljubljana;Slovenia.;Faculty of Mathematics;Physics;U. Ljubljana
中科院分区：
文献类型：
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作者：
J. Jaklic;P. J. Institute;Ljubljana;Slovenia.;Faculty of Mathematics;Physics;U. Ljubljana
我们回顾了最近的结果掺杂反铁磁体的性质，获得的数值分析的平面t-J模型使用新的有限温度Lanczos方法的小相关系统。首先，我们简要地总结了我们目前对铜酸盐反常正常态性质的理解，并提出了电子相图，唯象方案和模型在这方面提出的。然后更详细地描述了数值方法。下面的章节专门讨论t-J模型的各种静态和动态特性。在热力学性质中，计算了化学势、熵和比热。在讨论电学性质时，重点是平面光电导率和直流电阻率。磁性涉及静态和动态自旋结构因子，如通过磁化率测量、NMR弛豫和中子散射以及轨道电流贡献所测量的。电子光谱功能的分析，研究光电发射实验，以及它们与c轴电导率的关系，如下。最后讨论了密度涨落、电子拉曼散射和热电势。只要可行，就与实验数据进行比较。一个普遍的结论是，t-J模型很好地捕捉了铜酸盐反常正常态性质的主要特征，对于一些量，甚至是定量的协议。结果表明，几个动力学量表现出在中间掺杂一种新的普遍行为符合边际费米液体的概念，这似乎是从一个大的简并状态和掺杂的反铁磁体引起的挫折。
We review recent results for the properties of doped antiferromagnets, obtained by the numerical analysis of the planar t-J model using the novel finite-temperature Lanczos method for small correlated systems. First we briefly summarize our present understanding of anomalous normal-state properties of cuprates, and present the electronic phase diagram, phenomenological scenarios and models proposed in this connection. The numerical method is then described in more detail. The following sections are devoted to various static and dynamical properties of the t-J model. Among the thermodynamic properties the chemical potential, entropy and the specific heat are evaluated. Discussing electrical properties the emphasis is on the planar optical conductivity and the d.c. resistivity. Magnetic properties involve the static and dynamical spin structure factor, as measured via the susceptibility measurements, the NMR relaxation and the neutron scattering, as well as the orbital current contribution. The analysis of electron spectral functions, studied by photoemission experiments, and their relation to the c-axis conductivity, follows. Finally we discuss density fluctuations, the electronic Raman scattering and the thermoelectric power. Whenever feasible a comparison with experimental data is performed. A general conclusion is that the t-J model captures well the main features of anomalous normal-state properties of cuprates, for a number of quantities the agreement is even a quantitative one. It is shown that several dynamical quantities exhibit at intermediate doping a novel universal behaviour consistent with a marginal Fermi-liquid concept, which seems to emerge from a large degeneracy of states and a frustration induced by doping the antiferro magnet.