Theoretical Investigation On Electron Correlation Of Nonsequential Double Ionization Of Hydrogen Molecules In Strong Laser Fields

The interaction between light and material has being one of the most significant tasks in the strong-field physics in the past thirty years.In recent years,the rapid development of the ultrashort and strong intensity laser pulse technology provides the new tools to insight the interaction between light and material.The great development of laser technology has made the research of light-mater interaction extending into the domain of strong-field physics.A series of novel phenomena of strong-field physics appeared.The molecular nonsequential double ionization(NSDI)is particularly interesting,because it highly reflects the electron correlation behavior.NSDI of molecules in intense laser fields involves many physical processes,and the electron-electron correlation provides a simple model for studying the general phenomenon of correlation effects.In this paper,we study the electron correlation of NSDI of the hydrogen molecule in the strong-field by using the method of the classical ensemble approach.The studies are as follows:(1)We study the momentum distributions of the fast and the slow electrons of the hydrogen molecule,indicating that electrons are mainly emitted in the same direction after recollision.The correlated electron momentum distribution of the recollision-impact ionization(RII)and the recollision-induced excitation with subsequent ionization(RESI)mechanisms are simulated separately,which indicates that the RII electrons show positive correlation.Finally,the analysis of the momentum distribution of the final momentum ?the momentum distribution of the initial momentum ?the momentum distributions at different moments and the two orbital mechanisms can show that the Coulomb force plays a major role in the RII.(2)The influence of the laser intensity parameters on the electronic correlation was explored.The results show that the momentum distribution of RESI does not change significantly with the increase of the intensity of the laser field,and the change of the momentum distribution of RII directly affects with the increase of the intensity of the laser field.The increase in the intensity of the laser field causes the electronic correlation to change,and the correlation of the electrons is related to the intensity of the laser field.We also change the laser ellipticity polarization parameters,the results show that with the increase of the ellipticity,the momentum distribution of the electron pair is not changed,but the momentum of the electron pair is increased,and the correlation of the corresponding electron pair is not related to the elliptical polarization of the laser.