Quantitative theory for electron-nuclear energy sharing in molecular ionization

Abstract

The dynamics of molecules in strong laser fields is much more complicated than that of atoms. For example, molecules can break up through dissociative single ionization, in which the electronic dynamics and nuclear dynamics are strongly correlated with each other. In this work we develop a quantitative theory based on the strong-field approximation to describe the dissociative single ionization of a hydrogen molecule, which allows us to schematically investigate the electron-nuclear energy sharing in the dissociative and the nondissociative single ionization of ${\text{H}}_{2}$ induced by intense laser pulses. Under different parameters of the laser pulse, we are able to discuss various types of dynamics in the framework of energy sharing, such as bond softening, dynamical quenching, vibrational trapping, and inverse bond hardening. In particular, we find drastic differences in the electron-nuclear energy sharing for UV and IR pulses. The current theoretical framework can potentially be extended to examine other strong-field phenomena in which the dynamics of different particles are correlated.