Application of a time-of-flight spectrometer with delay-line detector for time- and angle-resolved two-photon photoemission
Application of a time-of-flight spectrometer with delay-line detector for time- and angle-resolved two-photon photoemission
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DOI：
10.1016/j.elspec.2015.03.009
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发表时间：
2015-07-01
影响因子：
1.9
通讯作者：
Hoefer, U.
中科院分区：
文献类型：
--
作者：
Damm, A.;Guedde, J.;Hoefer, U.
我们描述了一台能够同时获得低能光电子在平行于表面的二维方向上的能量和动量分布的飞行时间电子能谱仪的设计和工作。我们讨论了它的能力和局限性，特别是在脉冲激光的时间分辨和角度分辨双光子光电发射(2PPE)方面。通过给出铜(001)面上第一(n=1)像势态的动量相关电子动力学的2PPE数据，验证了该光谱仪的性能。数据揭示了衰变动力学对具有单次对称性的样品方位的微弱但系统的依赖性，我们将其归因于标称平坦表面上的小剩余台阶密度。(C)2015爱思唯尔B.V.保留所有权利。
We describe the design and operation of a time-of-flight electron spectrometer which is capable of simultaneously acquiring the energy and momentum distribution of low-energy photoelectrons in two dimensions parallel to the surface. We discuss its capabilities and limitations in particular for time- and angle-resolved two-photon photoemission (2PPE) with pulsed lasers. The performance of the spectrometer is demonstrated by presenting 2PPE data on the momentum-dependent electron dynamics of the first (n=1) image-potential state on Cu(001). The data reveal a weak but systematic dependence of the decay dynamics on sample azimuth with one-fold symmetry which we attribute to a small residual step density on the nominal flat surface. (C) 2015 Elsevier B.V. All rights reserved.