Tracking the electron recapture in dissociative frustrated double ionization of D2

By measuring the ejected neutral and ionic fragments as well as the freed electron in coincidence, we track the laser induced dissociative frustrated double ionization (FDI) of D2, in which process one of the two tunneled electrons is eventually recaptured by the outgoing nuclei of the breaking molecule after the conclusion of the femtosecond laser fields. The dynamics are investigated in a pump-probe scheme by using an elliptically and linearly polarized few-cycle laser pulses with tunable time delay. The distinct momentum distributions of the escaped electrons governed by the light polarizations allow us to identify from which laser fields, i.e., the pump or the probe fields, the electron is released and thus deduce the origin of the recaptured one. Our results show that the electron released in the second ionization step after the stretching of molecular bond is favored to be recaptured in the dissociative FDI of molecules.