Exploration of the nonsequential double-ionization process of a Mg atom with different delay time in few-cycle circularly polarized laser fields

Using the three-dimensional classical ensemble method, we investigate the nonsequential double-ionization (NSDI) process of Mg in few-cycle circularly polarized laser fields. We demonstrate the time evolution of the distribution of the electron energy, the repulsion energy between double-ionized electrons, the distance between the nucleus and double-ionized electrons, and the momentum of double-ionized electrons. By analyzing these theoretical results, we find that a few-cycle pulse would allow a single recollision event. In addition, the correlated momentum distribution, the angular distribution between double-ionized electrons, and the ion momentum distribution with different delay time, which is the time interval between final double ionization and recollision, are also demonstrated and the results show that the delay time plays a key role in electron emission processes.