Koralek J D, Douglas J F, Plumb N C, Sun Z, Fedorov A V, Murnane M M, Kapteyn H C, Cundiff S T, Aiura Y, Oka K, Eisaki H, Dessau D S
Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA.
Phys Rev Lett. 2006 Jan 13;96(1):017005. doi: 10.1103/PhysRevLett.96.017005. Epub 2006 Jan 11.
A new low photon energy regime of angle-resolved photoemission spectroscopy is accessed with lasers and used to study the high T(C) superconductor Bi2Sr2CaCu2O(8+delta). The low energy increases bulk sensitivity, reduces background, and improves resolution. With this we observe spectral peaks which are sharp on the scale of their binding energy--the clearest evidence yet for quasiparticles in the normal state. Crucial aspects of the data such as the dispersion, superconducting gaps, and the bosonic coupling kink are found to be robust to a possible breakdown of the sudden approximation.
利用激光进入角分辨光电子能谱的一个新的低光子能量区域，并用于研究高温超导体Bi2Sr2CaCu2O(8+δ)。低能量提高了体灵敏度，降低了背景，并提高了分辨率。据此，我们观察到在其结合能尺度上尖锐的光谱峰——这是正常态准粒子迄今最清晰的证据。发现数据的关键方面，如色散、超导能隙和玻色子耦合扭结，对于突然近似可能失效具有鲁棒性。
