Quantum electrodynamic description of the neutral hydrogen molecule ionization

TL;DR

This paper presents a quantum electrodynamic framework for understanding the ionization dynamics of the hydrogen molecule, revealing how dissipation, particle influx, and initial states influence ionization pathways and stabilization.

Contribution

It introduces a comprehensive first-principles approach combining QED and Lindblad dynamics to analyze hydrogen molecule ionization, highlighting control parameters and ionization limits.

Findings

Universal formation of neutral H2 molecule across regimes

Photon dissipation accelerates system stabilization

Ionization probability limited to 3/4 by orbital hybridization

Abstract

The ionization dynamics of a hydrogen molecule, serving as a fundamental benchmark in quantum chemistry, is investigated within a comprehensive framework combining quantum electrodynamics and the Lindblad master equation. This approach enables a first-principles description of light--matter interactions while accounting for dissipative processes and external particle influx. We systematically explore the system's evolution across three distinct regimes: closed, dissipative open, and influx-driven open quantum systems. Our results reveal a universal tendency towards the formation of the neutral hydrogen molecule ($|\rm{H}_2\rangle$) across all configurations. The dissipation strengths for photons ($\gamma_\Omega$), electrons ($\gamma_e$), and phonons ($\gamma_\omega$) are identified as critical control parameters, with $\gamma_\Omega$ significantly accelerating system stabilization. Furthermore, the introduction of particle influx ($\mu_k$) leads to a complex redistribution of energy, notably populating the atomic state ($|\rm{H},\rm{H}\rangle$). The ionization pathway is exquisitely sensitive to the initial quantum state, dictated by the composition and number of photons, which governs the accessible spin-selective excitation channels. This is conclusively demonstrated in a model with an embedded anode, where the maximum ionization probability is fundamentally constrained to $\frac{3}{4}$ by orbital hybridization. This study provides a unified theoretical foundation for quantum-controlled chemistry, with direct implications for future experiments in cavity QED and quantum information processing.