Nuclear kinetic energy spectra ofD2+in an intense laser field: Beyond the Born-Oppenheimer approximation

Abstract

Simultaneously, the vibrational nuclear dynamics and full dimensional electronic dynamics of the deuterium molecular ion exposed to the linear polarized intense laser field are studied. The time dependent Schrödinger equation of the aligned D 2 + with the electric laser field is solved for the simulation of the complicated dissociative ionization processes and compared with the recent related experimental results. In this work, the R-dependent ionization rate and the enhanced ionization phenomenon beyond the Born-Oppenheimer approximation (BOA) are introduced and calculated. The substructure of the nuclear kinetic energy release spectra are revealed as the Coulomb explosion energy spectra and dissociation energy spectra in the dissociation-ionization channel. The significant and trace of these distinct sub-spectra in the total spectra comparatively are displayed and discussed.

Dissociative double ionization ofH2andD2: Comparison between experiment and Monte Carlo wave packet calcu

“…2 obtained with pulses of the exact same pulse characteristics are given and the agreement between theory and the experiments is very convincing. Compared to previous models [4][5][6] we obtain better agreement with the experimental peak positions at 5.0, 5.5, and 6.7 eV and the first indication of a high-energy shoulder at >8 eV.…”

“…Unlike the short pulses, pulses of 140 fs or longer offer plenty of time to dissociate and hence all but the few molecules ionized very late in the pulse will reach regions of enhanced ionization. TDSE calculations using only a single ionization time [6] for the first ionization may, for this reason, reproduce the experimental results, while the simple two-state model of [4,5] is insufficient in this regime.…”

“…Studying the nuclear dynamics, it is possible to extract the kinetic energy release (KER) spectrum and to explain the origin of different structures in this spectrum. Contrary to other recent theoretical approaches [4][5][6], the MCWP theory contains all possible instants of the first ionization, and is so computationally efficient that also focal volume averaging can be performed. Both effects are important to obtain good agreement with experiments.…”

Effect of nuclear motion on high-order-harmonic generation ofH2+in intense ultrashort laser pulses

“…As stated above, the theoretical results on the HHG yield on 1D H 2 ) with electron cylindrical coordinate (z, ρ) with respect to the molecular center of mass and internuclear distance R, for both z and R parallel to the laser polarization direction, can be read (after elimination of the center-of-mass motion) as [26][27] …”

Probing two-center interference in H2+using chirped pulses

“…The interplay of electronic levels, i.e., the 1sσ g and 2pσ u electronic states, in the strong-field multiphoton ionization dynamics of H + 2 , was recently investigated both experimentally [2,3] and theoretically [4,5], applying near-infrared laser pulses a few tens of fs of duration. The observed modulations in the resulting kinetic energy release (KER) spectra of the Coulomb exploding nuclei were interpreted as a multiple pathway interference effect [3].…”