The Electronic Structure of the High Temperature Superconductors Studied by Angle Resolved Photoemission

[9624048]坎普萨诺角分辨光发射将用于研究高温超导体中的多体效应。该技术将提供以下方面的线索：(1)准粒子在正常和超导状态下的谱函数性质；(2)准粒子在正常和超导状态下的动量分布；(3)准粒子寿命对温度、动量和能量的依赖；(4)范霍夫奇点与正常和超导性质之间的关系。(5)洁净极限下超导间隙函数的性质。有限的初步结果表明，这些性质表现出不同寻常的行为，高温超导体仍然有许多有趣的物理惊喜等着我们。角分辨光发射将用于研究高温超导体中的多体效应。在这种技术中，样品用紫外线照射。这导致样品中的电子被射出。通过分析这些喷射电子的能量，可以得到样品中电子的状态。在传统材料中，这些信息可以帮助我们理解材料是如何携带电流的，以及它是如何在冷却时变成超导的。然而，高温超导体的行为与传统材料不同。这些材料中的电子相互作用，一个电子的运动与其他电子的运动密切相关。发生这种情况的材料称为“强相关材料”。该提案试图提供“光谱分布”的直接测量方法。后者测量从样品中添加或移除电子的概率。这将导致对高温超导体新电子特性的理解。*＊*

9624048 Campuzano Angle-Resolved Photoemission will be used to study many- body effects in high temperature superconductors. The technique will provide clues on (1) the nature of the spectral function of the quasiparticles in the normal and superconducting states, (2) the momentum distribution of the normal and superconducting states, (3) the dependence of the quasiparticle lifetime on temperature, momentum and energy, (4) the relationship between the van Hove singularity and the normal and superconducting properties, (5) the nature of the superconducting gap function in the clean limit. Limited preliminary results indicate that these properties exhibit unusual behavior, and that the high temperature superconductors still have many interesting Physics surprises in store for us. %%% Angle-Resolved Photoemission will be used to study many- body effects in high temperature superconductors. In this technique, the sample is irradiated with ultra-violet light. This causes the electrons in that sample to be ejected. By analyzing the energies of those ejected electrons, the state of the electrons in the sample can be obtained. This information can, in conventional materials, lead to understand how the material carries current, and how it becomes superconducting upon cooling. However, high temperature superconductors do not behave like conventional materials. The electrols in these materials interact with each other and the motion of one electron is strongly correlated with the motion of other electrons. Materials in which this occurs are called "Strongly Correlated Materials". The proposal seeks to provide a direct measurement of the "spectral distribution". The latter measures the probability of adding or removing an electron from the sample. This will lead to the understa nding of the novel electronic properties of high temperature superconductors. ***