Two-electron effects pervading the formation of highly excited neutral atoms in the break-up of strongly driven H$_{2}$

TL;DR

This paper provides a theoretical analysis of the formation of highly excited neutral hydrogen atoms during the breakup of strongly driven H₂ molecules, revealing two key mechanisms and predicting a new asymmetric energy sharing feature.

Contribution

It introduces the first theoretical model explaining the formation of excited neutral H atoms in strongly driven H₂, identifying two mechanisms and predicting a novel energy sharing phenomenon.

Findings

Identification of non-sequential and sequential mechanisms.

Prediction of asymmetric energy sharing with increasing intensity.

Demonstration of electron influence on nuclear motion.

Abstract

We present the first theoretical treatment of the formation of highly excited neutral H atoms (H$^{*}$) for strongly driven H$_{2}$. This process, with one electron ionizing and one captured in a Rydberg state, was recently reported in an experimental study in Phys. Rev. Lett {\bf 102} 113002 (2009). We show that two mechanisms underlie this process: a non-sequential one resembling non-sequential double ionization, and a sequential one resembling double ionization through enhanced ionization. We also predict a new feature, asymmetric energy sharing between H$^{*}$ and H$^{+}$ with increasing intensity. This feature is a striking demonstration of the influence the electron has on the nuclear motion.