Photoionization of aligned excited states in neon by attosecond laser pulses

TL;DR

This paper investigates how electron correlation influences ionization dynamics of aligned excited neon atoms under attosecond laser pulses, revealing the dominance of correlation-assisted channels and polarization-dependent electron emission patterns.

Contribution

It introduces a numerical approach using TD-RASSCF to accurately model electron correlation effects in photoionization of excited neon states under attosecond pulses.

Findings

Correlation-assisted ionization channels can dominate over non-correlated channels.

Circular polarization causes a rotation in photoelectron momentum distribution.

Electron correlation effects are essential for accurate photoelectron emission modeling.

Abstract

We describe numerically the ionization process induced by linearly and circularly polarized XUV attosecond laser pulses on an aligned atomic target, specifically, the excited state Ne$^*(1s^22s^22p^5[{}^2\text{P}^\text{o}_{1/2}]3s[^1\text{P}^o])$. We compute the excited atomic state by applying the time-dependent restricted-active-space self-consistent field (TD-RASSCF) method to fully account for the electronic correlation. We find that correlation-assisted ionization channels can dominate over channels accessible without correlation. We also observe that the rotation of the photoelectron momentum distribution by circularly polarized laser pulses compared to the case of linear polarization can be explained in terms of differences in accessible ionization channels. This study shows that it is essential to include electron correlation effects to obtain an accurate description of the photoelectron emission dynamics from aligned excited states.