Quantum optical analysis of high-order harmonic generation in H$_2^+$ molecular ions

TL;DR

This paper provides a quantum optical analysis of high-order harmonic generation in H$_2^+$ molecular ions, revealing entanglement and non-classical light states, with implications for quantum technology applications.

Contribution

It introduces a quantum optical framework for HHG in molecules, demonstrating entanglement and non-classical light states, advancing the understanding of quantum effects in molecular HHG.

Findings

Entanglement between electron and light states post-interaction

Generation of non-classical states of light in specific frequency modes

Potential for quantum technology applications using molecular HHG

Abstract

We present a comprehensive theoretical investigation of high-order harmonic generation in H$_2^+$ molecular ions within a quantum optical framework. Our study focuses on characterizing various quantum optical and quantum information measures, highlighting the versatility of HHG in two-center molecules towards quantum technology applications. We demonstrate the emergence of entanglement between electron and light states after the laser-matter interaction. We also identify the possibility of obtaining non-classical states of light in targeted frequency modes by conditioning on specific electronic quantum states, which turn out to be crucial in the generation of highly non-classical entangled states between distinct sets of harmonic modes. Our findings open up avenues for studying strong-laser field-driven interactions in molecular systems, and suggest their applicability to quantum technology applications.