Non-adiabatic effects on resonant two-photon dissociation of HD+ in the presence of two frequency laser fields

Abstract

The time-dependent dissociation probabilities, lineshapes of dissociation rates and branching ratios of photofragments between the neutral hydrogen and deuterium channels have been investigated for resonant two-photon dissociation of HD+ from the ground level in the presence of two laser fields of different intensities I1, I2 and frequencies omega 1, omega 2 using the resolvent operator formalism. The symmetry breaking due to non-adiabatic (NA) interactions causes splitting between the two asymptotic channels, unlike the Born-Oppenheimer (BO) approximation. Simultaneous dissociation to the continua of the two electronic states at two different energies occurs through the absorption of either omega 1+ omega 2 or 2 omega 1 photons. Only the field of frequency omega 1 was considered to resonantly couple the near-resonant level nu '=17, J'=1 or nu '=18, J'=1 to the ground level nu =0, J=0. Non-resonant discrete and continuum states significantly affect the dissociation process in the case of high intensity fields. The electric field gauge (E.d) form of interaction Hamiltonian has been used in the computation of various laser-dependent parameters. The results with NA coupling included are found to deviate appreciably from those obtained with the BO approximation.