Onset of ionic coherence and ultrafast charge dynamics in attosecond molecular ionisation
Onset of ionic coherence and ultrafast charge dynamics in attosecond molecular ionisation
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DOI：
10.1039/c9cp03074c
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发表时间：
2019-08-28
影响因子：
3.3
通讯作者：
Ruberti, M.
中科院分区：
文献类型：
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作者：
Ruberti, M.
这里提出了一个完全从头计算的理论框架，用于模拟相关的多电子动力学过程中发生的和出现的分子电离的阿秒激光脉冲。这是基于时间相关（TD）版本的B样条限制相关空间（RCS）-代数图解构造（ADC）方法，与完整的描述的光电子和电子相关效应，如震荡过程和通道间耦合。在分子离子的超快电荷动力学的性质是阐明通过定量预测的程度的电子相干性和本征态含量的制备的分子阳离子态，超出了常用的突然近似。这里提出的乙炔和乙烯分子的结果表明，即使在高光子能量制度的模拟空穴动力学是定量不同的突然近似的预测。此外，对于高带宽电离脉冲，在高度激发的震荡状态下的阳离子与发射的慢光电子之间的残余相互作用引起离子系统中的相干性损失，其可以在电离后的前几个飞秒持续。
Here is presented a fully ab initio theoretical framework for simulating the correlated many-electron dynamics occurring during and emerging from molecular ionisation by attosecond laser pulses. This is based on the time-dependent (TD) version of the B-spline restricted correlation space (RCS)-algebraic diagrammatic construction (ADC) method, with the full description of the photoelectron and inclusion of electron correlation effects, such as shakeup processes and inter-channel couplings. The nature of the ultrafast charge dynamics in the molecular ion is elucidated by quantitatively predicting the degree of electronic coherence and eigenstate content of the prepared molecular cationic state, beyond the commonly used sudden approximation. The results presented here for the acetylene and ethylene molecules show that even in the high photon energy regime the simulated hole dynamics is quantitatively different from the prediction of the sudden approximation. Moreover, for high-bandwidth ionising pulse, the residual interaction between the cation, in highly-excited shake-up states, and the emitted slow photoelectron gives rise to a loss of coherence in the ionic system which can persist for the first few femtoseconds after ionisation.