Laser based angle-resolved photoemission, the sudden approximation, and quasiparticle-like spectral peaks in Bi2Sr2CaCu2O8+δ
Laser based angle-resolved photoemission, the sudden approximation, and quasiparticle-like spectral peaks in Bi2Sr2CaCu2O8+δ
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DOI：
10.1103/physrevlett.96.017005
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发表时间：
2006-01-13
影响因子：
8.6
通讯作者：
Dessau, DS
中科院分区：
文献类型：
--
作者：
Koralek, JD;Douglas, JF;Dessau, DS
本文报道了一种新的低光子能量区的角分辨光电子能谱，并用于研究高温超导体Bi_2Sr_2CaCu_2 O_（8 + δ）。低能量增加了体灵敏度，减少了背景，并提高了分辨率。这样，我们就可以观察到在它们的结合能尺度上非常尖锐的光谱峰--这是关于准粒子处于正常状态的最清楚的证据。关键方面的数据，如色散，超导间隙，和玻色子耦合扭结被发现是强大的突然近似的可能的故障。
A new low photon energy regime of angle-resolved photoemission spectroscopy is accessed with lasers and used to study the high T-c superconductor Bi2Sr2CaCu2O8+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.