Conditions for enhancement of chemical reactions in gas phase inside a dark cavity

TL;DR

This paper investigates how dark cavities can enhance certain asymmetric gas-phase chemical reactions by coupling to quantum-electrodynamics modes, providing theoretical conditions and simulations to guide experimental efforts.

Contribution

It introduces a theoretical framework using non-Hermitian quantum mechanics to identify reactions that can be enhanced by dark cavities, focusing on asymmetric reactions in the gas phase.

Findings

Asymmetric reactions can be enhanced by dark cavities.

Symmetric reactions show negligible enhancement.

Theoretical conditions guide experimental design.

Abstract

Enhancing chemical reactions, such as $A+B \to [\textit{activated complex}]^\# \to C+D$, in gas phase through its coupling to quantum-electrodynamics (QED) modes in a dark cavity is investigated. The main result is that the enhancement of the reaction rate by a dark cavity is for asymmetric reactions (products different from reactants.) Notice that in addition to the cavity been dark, the reactants are in their ground electronic and vibrational states, i.e., it is indeed dark. Theoretical derivation, utilizing the non-Hermitian formalism of quantum mechanics (NHQM), provides conditions and guidelines for selecting the proper type of reactions that can be enhanced by a dark cavity. Nevertheless, the time-dependent simulations of such experiments can be carried out using the standard (Hermitian) scattering theory (but including the conditions derived via NHQM). We believe that this work opens a gate to new types of studies and hopefully helps to close the gap between theory and experiments in this fascinating, relatively new field of research. As an example, we demonstrate that the asymmetric reaction rates of $O+D_2\to [ODD]^{\#} \to OD+D$ and $H+ArCl \to [ArHCl]^{\#} \to H+Ar+Cl$ can be enhanced by a dark cavity. Contrary, the dark cavity effect on the symmetric reaction of hydrogen exchange in methane will be negligible.