Theoretical investigation of the Freeman resonance in the dissociative ionization of H2+

The dissociative ionization of H-2(+) in linearly polarized, 400 nm laser pulses is simulated by solving a three-particle time-dependent Schrodinger equation in full dimensionality. The joint energy spectra (JES) are computed for cos 8 and flat-top envelopes using the time-dependent surface flux (tSurff) methods. In JES, the energy sharing of N photons with frequency omega by nuclear kinetic energy release (KER) E-N and electronic KER E-e is well described by E-N + E-e = N omega - U-p + E-0 for the cos(8) envelope, but satisfy E-N + E-e= N omega + E-0 for the flat-top envelope, exposing a deviation of the ponderomotive energy U-p, where E-0 is the ground energy of H-2(+) and this observation has been observed in experiments. The analysis of the wave function for electrons and protons after the pulse are presented, where we find U-p is absorbed by the Freeman resonances between two excited ungerade states of H-2(+).