Microscopic analysis of above-threshold ionization driven by squeezed light

TL;DR

This paper develops a quantum optical theory for above-threshold ionization driven by squeezed light, revealing enhanced light-matter coupling, altered ionization times, and significant entanglement with non-Gaussian properties.

Contribution

It introduces a microscopic quantum optical model for ATI with squeezed light, highlighting the impact of non-classical light on electron dynamics and entanglement.

Findings

Squeezed light enhances light-matter coupling in ATI.

Ionization times are significantly affected by non-classical light.

The quantum optical state exhibits non-Gaussian features depending on squeezing and ionization events.

Abstract

Above-threshold ionization (ATI) is a strong-field-driven process where electrons absorb more photons than required for ionization. While ATI dynamics and outputs are well-understood when driven by classical, perfectly coherent light, the recent development of non-classical light sources for strong-field phenomena has spurred interest in their effect on the involved electron dynamics. In this work, we present a microscopic quantum optical theory describing ATI under the influence of strong squeezed light. We observe that squeezed light significantly enhances the coupling between light and matter, making their mutual backaction more important than under classical driving. This backaction profoundly impacts the electronic ionization times, as well as the non-classical properties of the joint electron-light state. This results in pronounced entanglement features, both immediately after ionization, and at later times. These entanglement features are reflected in the properties of the quantum optical state of the driving field revealing notable non-Gaussian features that depend on both, the amount of squeezing, and the number of ionization events occurring during the interaction.