Semiclassical description of photoionization microscopy
Semiclassical description of photoionization microscopy
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DOI：
10.1103/physreva.68.012709
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发表时间：
2003-07
影响因子：
2.9
通讯作者：
C. Bordas;F. Lépine;C. Nicole;M. Vrakking
中科院分区：
文献类型：
--
作者：
C. Bordas;F. Lépine;C. Nicole;M. Vrakking
最近，有实验报道，当在速度图成像设备中检测到在氙的阈值光电离中喷射的光电子时，观察到几何干涉图案[C.妮可等人，物理学。莱特牧师。 88、133001(2002)]。这种技术称为光电离显微镜，依赖于电子从原子移动到观察平面的各种轨迹之间存在的干扰。与之前与氢情况相关的预测不同，干涉图样的结构随着鞍点以上的多余能量而平稳演化，并且仅受连续斯塔克共振的存在的微弱影响。在本文中，我们描述了该过程的半经典分析，并提出了与实验结果非常吻合的数值模拟。结果表明，背景贡献在观测中占主导地位，这与氢系统预期的行为相反，氢系统的干涉图案在准离散斯塔克共振上有本质上的不同。
Recently, experiments have been reported where a geometrical interference pattern was observed when photoelectrons ejected in the threshold photoionization of xenon were detected in a velocity-map imaging apparatus [C. Nicole et al., Phys. Rev. Lett. 88, 133001 (2002)]. This technique, called photoionization microscopy, relies on the existence of interferences between various trajectories by which the electron moves from the atom to the plane of observation. Unlike previous predictions relevant to the hydrogenic case, the structure of the interference pattern evolves smoothly with the excess energy above the saddle point and is only weakly affected by the presence of continuum Stark resonances. In this paper, we describe a semiclassical analysis of this process and present numerical simulations in excellent agreement with the experimental results. It is shown that the background contribution dominates in the observations, as opposed to the behavior expected for hydrogenic systems where the interference pattern is qualitatively different on quasidiscrete Stark resonances.