Laser assisted charge transfer reactions in slow ion–atom collisions: Coupled dressed quasimolecular-states approach

Semiclassical coupled dressed quasimolecular states (DQMS) approaches are presented for the nonperturbative treatment of charge transfer reactions at low collision velocities and high laser intensities. The DQMS are first obtained via the Floquet theory. The laser assisted collision process can then be treated as the electronic transitions among the DQMS driven by the nuclear motion only. The expansion of the total electronic wave function in a truncated DQMS basis results in a set of coupled adiabatic equations. The adiabatic DQMS and their associated quasienergies (depending parametrically upon the internuclear separation R) exhibit regions of avoided crossings, where the electronic transition probabilities are large due to strong radial couplings induced by the nuclear movement. By further transforming the adiabatic DQMS into an appropriate diabatic DQMS representation, defined via the vanishing of the aforementioned radial couplings, we obtain a new set of coupled diabatic equations which offer comput...