JILA, Boulder, Colorado 80303, USA.
Phys Rev Lett. 2012 Aug 17;109(7):073004. doi: 10.1103/PhysRevLett.109.073004. Epub 2012 Aug 16.
Using a simple model of strong-field ionization of atoms that generalizes the well-known 3-step model from 1D to 3D, we show that the experimental photoelectron angular distributions resulting from laser ionization of xenon and argon display prominent structures that correspond to electrons that pass by their parent ion more than once before strongly scattering. The shape of these structures can be associated with the specific number of times the electron is driven past its parent ion in the laser field before scattering. Furthermore, a careful analysis of the cutoff energy of the structures allows us to experimentally measure the distance between the electron and ion at the moment of tunnel ionization. This work provides new physical insight into how atoms ionize in strong laser fields and has implications for further efforts to extract atomic and molecular dynamics from strong-field physics.
使用一个将著名的 1D 三阶段模型推广到 3D 的强场原子电离简单模型，我们表明，氙气和氩气激光电离产生的实验光电子角分布显示出明显的结构，这些结构对应于在强烈散射之前多次经过其母离子的电子。这些结构的形状可以与电子在激光场中被驱离母离子的特定次数相关联。此外，对结构截止能的仔细分析使我们能够从实验上测量隧穿电离瞬间电子和离子之间的距离。这项工作为我们提供了关于原子在强激光场中电离的新的物理见解，并对进一步从强场物理中提取原子和分子动力学的努力具有重要意义。
