Attosecond-pump attosecond-probe spectroscopy in non-equilibrium ensembles

理解原子和分子的行为需要理解构成这些系统的电子和原子核的动力学。这种动态的典型时间尺度是飞秒（10-15秒）。我们需要使用比这更短的光脉冲来启动动力学，然后捕捉它。动力学是由量子相干性驱动的。在本项目中，我们将使用新的计算例程来增强具有时间相关代码的最先进的r矩阵，以跟踪量子相干性。这将使我们能够将几个单独的计算合并为一个总体计算。这项工作将为未来在世界领先的激光设备上进行阿秒泵浦阿秒探测实验提供支持，并能够阐明由泵浦激光引起的量子动力学。我们将把这个方法应用到自由电子激光设备中涉及到外层和内层电子发射的顺序电离的演示问题。我们还研究了该方法预测特定动力学最优参数的能力。

Understanding how atoms and molecules behave requires understanding of the dynamics of electrons and nuclei that make up these systems. The typical timescale for this dynamics is the femtosecond (10-15 s). We need to use light pulses shorter than this to initiate the dynamics and then to capture it. The dynamics is driven by quantum coherence. In this project, we will enhance the state-of-the-art R-matrix with time dependence code with new computational routines to keep track of the quantum coherence. This will enable us to combine several individual calculations into one overarching calculation. This work will provide capability to support future attosecond-pump attosecond-probe experiments at world-leading laser facilities, and capability to elucidate quantum dynamics induced by the pump laser. We will apply the approach to demonstration problems involving sequential ionization at free-electron laser facilities involving the emission of both outer and inner-shell electrons. We also investigate the capability of the approach to predict optimal parameters for specific dynamics.