Quantum versus semi-classical signatures of correlated triple ionization in Dalitz plots

TL;DR

This study compares quantum and semi-classical models of three-electron ionization in neon under intense laser fields, revealing key signatures in Dalitz plots and emphasizing the importance of the ECBB model for accurate predictions.

Contribution

It introduces a comparison between quantum and semi-classical models, highlighting the ECBB model's superior agreement with quantum results in correlated triple ionization signatures.

Findings

Better agreement between quantum and ECBB models in Dalitz plot signatures.

The central 'spot' on Dalitz plots corresponds to direct triple ionization.

The width of the 'spot' depends on tunnel-ionization timing.

Abstract

We investigate correlated three-electron escape in Ne when driven by an intense, infrared laser field. We do so by employing a reduced-dimensionality quantum-mechanical model and two three-dimensional semi-classical models. One semi-classical model is a recently developed one that accounts with effective coulomb potentials for the interaction between two bound electrons (ECBB) while it fully accounts for all other interactions. The other semi-classical model is the Heisenberg one, which effectively accounts for the interaction of each electron with the core via a soft-core potential. We identify and compare the signatures of correlated three-electron escape for both quantum and semi-classical models on Dalitz plots and find a better agreement between the quantum and the ECBB model. We also show that a central ``spot'' on the Dalitz plots is reproduced by all models. Using the ECBB model we associate this ``spot'' with the direct triple ionization pathway and argue this to be the case also for the quantum model. Devising a simple classical model that accounts for the direct pathway of triple ionization, we show that the width of this spot in the Dalitz plots solely depends on the time of tunnel-ionization.