Science. 1995 Jan 20;267(5196):343-50. doi: 10.1126/science.267.5196.343.
Over the last several years there have been great improvements in the energy resolution and detection efficiency of angle-resolved photoemission spectroscopy. These improvements have made it possible to discover a number of fascinating features in the electronic structure of the high transition temperature (T(c)) superconductors: apparently bandlike Fermi surfaces, flat-band saddle points, and nested Fermi surface sections. Recent work suggests that these features, previously thought explainable only by one-electron band theory, may be better understood with a many-body approach. Furthermore, other properties of the high-T(c) superconductors, which are difficult to understand with band theory, are well described using a many-body picture. Angle-resolved photoemission spectroscopy has also been used to investigate the nature of the superconducting pairing state, revealing an anisotropic gap consistent with a d-wave order parameter and fueling the current debate over s-wave versus d-wave superconductivity.
在过去的几年中，角分辨光电子能谱的能量分辨率和探测效率有了很大的提高。这些改进使得人们有可能发现高温超导（T(c)）体电子结构中的一些引人入胜的特征：显然的类能带费米面、扁平能带鞍点和嵌套费米面部分。最近的工作表明，这些以前只能用单电子能带理论解释的特征，可能可以用多体方法更好地理解。此外，用能带理论很难理解的高温超导体的其他性质，用多体图像可以很好地描述。角分辨光电子能谱也被用于研究超导配对态的性质，揭示了与 d 波有序参数一致的各向异性能隙，这引发了当前关于 s 波与 d 波超导性的争论。
