Extracting partial decay rates of helium from complex rotation: autoionizing resonances of the one-dimensional configurations

TL;DR

This paper introduces a method to calculate partial autoionization rates of doubly excited helium states using complex rotation and wave function projections, revealing decay behaviors and aiding future atomic decay studies.

Contribution

It presents a novel approach combining complex rotation and wave function projection to analyze decay rates in one-dimensional helium models.

Findings

Stationary flux regions observed despite Coulomb long-range potential

Low-lying states decay mainly into the nearest ionization continuum

Method enables systematic analysis of decay rates in higher-dimensional models

Abstract

Partial autoionization rates of doubly excited one-dimensional helium in the collinear Zee and eZe configuration are obtained by means of the complex rotation method. The approach presented here relies on a projection of back-rotated resonance wave functions onto singly ionized $\textrm{He}^{+}$ channel wave functions and the computation of the corresponding particle fluxes. In spite of the long-range nature of the Coulomb potential between the electrons and the nucleus, an asymptotic region where the fluxes are stationary is clearly observed. Low-lying doubly excited states are found to decay predomintantly into the nearest single-ionization continuum. This approach paves the way for a systematic analysis of the decay rates observed in higher-dimensional models, and of the role of electronic correlations and atomic structure in recent photoionization experiments.