Light-induced nonadiabatic photodissociation of the NaH molecule including electron-rotation coupling

TL;DR

This study investigates how laser light induces nonadiabatic photodissociation in NaH molecules by exploring light-induced degeneracies, electronic-rotation coupling, and ultrafast nuclear dynamics through numerical simulations.

Contribution

It introduces a comprehensive model including multiple light-induced degeneracies and electron-rotation coupling to simulate NaH photodissociation dynamics.

Findings

Light-induced degeneracies significantly affect dissociation pathways.

Electronic-rotation coupling influences angular distributions of photofragments.

Simulations reveal detailed kinetic energy spectra and dissociation probabilities.

Abstract

It is well established that electronic conical intersections (CIs) in molecular systems can be induced by laser light, even in diatomic molecules. The emergence of these light-induced degeneracies leads to strong coupling among electronic, vibrational, and photonic modes, which significantly influences ultrafast nuclear dynamics. In this work, we perform pump-probe numerical simulations on the NaH molecule, considering the first three singlet electronic states- (X1{\Sigma}+(X), A1{\Sigma}+(A) and B1{\Pi}(B)) -and including several light- induced degeneracies in the theoretical model. To elucidate the ultrafast molecular dynamics, the combined effects of multiple light-induced nonadiabatic couplings and rotational motion of the nuclei, together with the situation when the electronic angular momentum projected onto the diatomic axis couples with the angular momentum of the nuclei has been studied. We then calculate key dynamical observables such as dissociation probabilities, kinetic energy release spectra, and angular distributions of the photofragments within and above the linear regime.