超短强激光脉冲作用于分子体系的核和电子动力学研究及其高效量子波包方法的发展

There are many interesting phenomena in the interact processes between the ultra-short strong laser pulses and molecule systems which arise much interest in strong laser physics field in recent years. However, due to the lack of efficient numerical method and computer resources, the correlated dynamics between electrons and nuclei and electrons themselves has not been investigated in detail. For example, currently there is no accurate quantum numerical model for precisely simulating how the multielectron ionization processes depend on the laser pulse. Even more, there are different answers when using different theoretical approaches to investigate the two-photon double ionizations of hydrogen molecule. Therefore, it is necessary to develop efficient and accurate numerical methods for describing such porcesses. In this project, we will aim at developing and utilizing efficient time-dependent quantum wavepacket method and ultimately to overcome these questions. First of all, for diatomic molecular systems, we will develope efficient wavepacket method in cylinder coordinate. The cylinder coordinates are very suitable to describe the ionization processes of diatomic molecules and incorporate the motion of nuclei. We will develope suitable DVR method in a mapped Fourier form, and efficient propagation method. Further we will parallel the code to impove its calculational efficiency. Using our developed method, we will investigate the two-photon double ionization of hydrogen molecule to find out the reasons of the differences between previous theoretical results, and study the interaction processes between linear H3+ and its isotopic systems and laser pulses to investigate how the multi-nuclear dynamics affect electronic dynamics. Then, we will combine with the MCTDHF method and our developed efficient DVR method in cylinder coordiantes, which can account for both nuclear and multi-electronic motion simultaneously, to study the physical mechanism of the multi-electron ionizations of molecules in various laser pulses, such as NO and CO systems.

超短强激光脉冲作用于分子体系是近年来强场物理研究的热点，但由于缺乏有效方法以及计算资源的限制，目前还不能够做到精确模拟电子关联以及核和电子之间的关联动力学问题，如多电子电离过程依赖于激光场条件的现象至今没有精确量子模拟、不同理论方法探讨H2双光子双电离过程的结果却存在差异等。因此，有必要发展高效精确的量子方法来描述这些过程。在本项目中，我们拟发展和利用高效的含时量子波包方法对这些问题进行精确研究。首先，发展基于柱坐标高效的量子含时波包方法，发展合适的DVR方法、映射函数方法以及优化的传播方法并应用到程序中，并行化，进一步提高计算效率，对H2的双光子双电离过程进行研究并找出之前理论结果差异的原因，研究线性H3+及其同位素分子体系中多核之间的耦合动力学过程对电子动力学过程的影响；其次，将发展的方法与MCTDHF方法结合，同时包含核运动和多电子运动，研究不同激光场下NO和CO分子多电子电离过程。

超短强激光脉冲作用于分子体系是近年来强场物理研究的热点，但由于缺乏有效方法以及计算资源的限制， 目前还不能够做到精确模拟电子关联以及核和电子之间的关联动力学问题，如多电子电离过程依赖于激光场条件的现象至今没有精确量子模拟、不同理论方法探讨 H2 双光子双电离过程的结果却存在差异等。 因此，有必要发展高效精确的量子方法来描述这些过程。 在本项目中，我们拟发展和利用高效的含时量子波包方法对这些问题进行精确研究。首先， 发展基于柱坐标高效的量子含时波包方法， 发展了采用映射函数结合高阶有限差分方法来描述径向自由度的数值方法，提高了计算效率；研究了采用数学上严格的MECS方法，来代替普通吸收势的衰减边界处波函数的方法，提高了吸收效率和数值计算效率；研究了核运动对于H2+分子产生高次谐波的影响；初步研究了如何采用格点方法来精确描述H2 的电子相关性。