Nuclear interference in dissociating of HD+in ultrashort laser fields

Abstract

The dissociation dynamics of HD + molecules is studied theoretically by numerically solving the timedependent Schrödinger equation in which the molecular vibrational and rotational degrees of freedom are included. Based on the Born-Oppenheimer approximation, the ground 1sσ g state and the excited 2pσ u state are taken into account, corresponding to two dissociative channels HD + →D + H + and HD + →H + D + , respectively. Two dissociative nuclear wave packets overlap and interfere after excited by two ultrashort laser pulses. The interference patterns can be controlled by varying the laser parameters and the dissociation probabilities are demonstrated for different laser fields. The kinetic energy-dependent distributions of the fragments are calculated using an asymptotic-flow expression in the momentum space. The branching ratio D, as a function of the delay time and the relative phase between two laser pulses, is also discussed.

Above-threshold dissociation of the molecular ion HD+ in a moderate-intensity femtosecond laser field from the calculation of time-of-flight spectra

“…Substantial effort has been devoted to theoretical studies of the dissociation of the HD + molecular ion [24][25][26][27][28][29][30][31]. For instance, the kinetic energy spectra for the dissociation of this system at high intensities (10 14~1 0 15 W/cm 2 ) were calculated by using the wavepacket method [24,26], which supported the experimental findings that absorption of 4 or 5 photons was occurring at high intensities.…”

“…For instance, the kinetic energy spectra for the dissociation of this system at high intensities (10 14~1 0 15 W/cm 2 ) were calculated by using the wavepacket method [24,26], which supported the experimental findings that absorption of 4 or 5 photons was occurring at high intensities. Besides the ATD dynamics, many other issues were also investigated, such as the control of the asymmetry branching ratio of the photofragments [28], the interferences between dissociative wavepackets [29], the preparation and probing of the coherent vibrational wavepacket [30], the steering of the electron localization [31], etc. Most of these studies were based on the calculation of the kinetic energy distribution of dissociated fragments, and to the best of our knowledge, the ATD process of the HD + molecular ion has not yet been thoroughly and quantitatively explained in a theory-versus-experiment comparison via a TOF spectrum.…”

Controlling strong-field fragments of HD+ with a synthesized two-color laser pulse

“…13 and 38–41, the simulation results indicated that the electron localization on the dissociation process of HD + can be controlled by manipulating the laser intensity, pulse duration and the CEP of the ultrashort femtosecond pulse. Subsequently, the schemes of two femtosecond laser pulses 42–44 have been employed to explore the possibility of controlling the branching ratio to different dissociation channels of HD + by tuning the laser frequency and delay time of the two femtosecond pulses. Moreover, a multi-pulse scheme has been proposed to control the branching ratio between the different dissociation fragments of HD + .…”

The “bound wavefunction” on the repulsive excited () state of the HD+ molecule

“…Moreover, in most of the theoretical treatments, the initial wavefunction is calculated based on the Born–Oppenheimer (B‐O) approximation (see e.g., Refs. [ ]). This approximation bases on the rationale that the nuclear kinetic energies are generally much smaller than those of electrons.…”