# Fingerprints of slingshot non-sequential double ionization on two-electron probability distributions

## TL;DR

This paper investigates the mechanisms of non-sequential double ionization in helium under specific laser conditions, identifying distinctive two-electron distribution signatures of the slingshot-NSDI pathway.

## Contribution

It reveals the properties of two-electron escape in slingshot-NSDI and identifies observable signatures in electron energy distributions.

## Key findings

- Slingshot-NSDI dominates at low intensities.
- Electrons escape with large, roughly equal energies in slingshot-NSDI.
- Distinct two-electron probability distribution features characterize the pathway.

## Abstract

We study double ionization of He driven by a near-single-cycle laser pulse at low intensities at 400 nm. Using a three-dimensional semiclassical model, we identify the pathways that prevail non-sequential double ionization (NSDI). We focus mostly on the delayed pathway, where one electron ionizes with a time-delay after recollision. We have recently shown that the mechanism that prevails the delayed pathway depends on intensity. For low intensities slingshot-NSDI is the mechanism that prevails. Here, we identify the differences in two-electron probability distributions of the prevailing NSDI pathways. This allows us to identify properties of the two-electron escape and thus gain significant insight into slingshot-NSDI. Interestingly, we find that an observable fingerprint of slingshot-NSDI is the two electrons escaping with large and roughly equal energies.