双色圆偏振激光作用下光电离中的电子涡旋研究

最近的研究表明，在双色圆偏振激光作用下，原子光电子动量分布中会呈现出新奇的电子涡旋结构，并吸引了国内外研究者的广泛兴趣。本项目我们深入研究双色圆偏振激光作用下光电离中的电子涡旋，主要内容包括：通过数值求解激光与原子相互作用的含时Schrödinger方程或强场近似理论方法，研究双色反旋圆偏振激光作用下，两束激光脉冲的时间延迟、相位、波长和旋性对电子涡旋的影响，比较分析多光子电离区和隧穿电离区光电离中的电子涡旋；通过分析不同路径产生的电子波包之间的干涉，研究交叉通道对电子涡旋和光电子角分布的影响；研究He+的二维简并激发态为初始条件时光电离中的电子涡旋，实现对电子涡旋的调控；研究双色同旋圆偏振激光作用下电子涡旋旋臂的旋转方向和轨迹，进一步分析电子涡旋的结构与激光矢势的旋转方向和轨迹的关系；应用阿秒微扰电离理论阐述电子涡旋产生的物理机制。

Recently a novel finding is that the atomic photoelectron momentum distributions (PMDs) showed vortex pattern by two-color circularly polarized laser pulses, which has attracted a great deal of attention. In this project, we deeply investigate the electron vortices in photoionization by two-color circularly polarized laser pulse. The main contents include: We investigate the effect of the time delay, carrier envelope phase, wavelength and helicity of the two laser pulses on the electron vortices by two-color circularly polarized laser pulses by numerically solving the time-dependent Schrödinger equation (TDSE) or strong field approximation (SFA) method, and we will demonstrate the electron vortices in photoionization in the multi-photon ionization regime and the tunneling ionization regime; We will investigate the electron vortices and the photoelectron angular distributions (PADs) by analyzing the cross channel contribution and the interference effects of coherent electron wave packets from different pathways; We also explore the electron vortices in photoionization of He+ when the two-dimensional degenerate excited state is as the initial input, which can realize the control of the electron vortices; The rotating direction and trajectory of the arms of electron vortices in photoionization by two-color co-rotating circularly polarized laser fields will be investigated, and the relationship between the vortex patterns and the rotating trajectory of laser vector potential will be further demonstrated. The attosecond perturbation ionization theory is employed to analyze the physical mechanisms of the generation of electron vortices.