Theory of strong-field ionization of aligned CO2

TL;DR

This paper develops a theoretical model for strong-field ionization of aligned CO2 molecules, accurately matching experimental data and revealing the influence of resonance states and limitations of existing theories.

Contribution

It introduces a new theoretical framework that accounts for resonance effects and explains discrepancies in previous semi-analytical models.

Findings

Ionization yields depend on molecular alignment and resonance states.

The new theory aligns with experimental results better than previous models.

Semi-analytical theories fail to account for electronic structure effects.

Abstract

A theoretical framework for studying strong-field ionization of aligned molecules is presented, and alignment-dependent ionization yields are computed for CO2. Our calculations are in unprecedented agreement with recent experiments. We find that the ionization process is affected by intermediate resonance states, and the alignment-dependent ionization yields do not follow the electron density of the initial states. The theory explains the breakdown of semi-analytical theories, like the molecular tunneling theory and strong-field approximation, were excited electronic structure is neglected.