Cooperative Chemical Reactions in Optical Cavities: A Complex Interplay of Mode Hybridization, Timescale Balance, and Pathway Interference

TL;DR

This study provides a detailed quantum dynamical analysis of how optical cavities influence chemical reaction rates through mode hybridization, energy exchange, and quantum interference, revealing complex and tunable reactivity modifications.

Contribution

It introduces a numerically exact quantum dynamical framework to understand cavity-modified chemical reactions, emphasizing the roles of mode hybridization and quantum interference.

Findings

Cavity-induced rate modifications depend on structural and environmental factors.

Resonant rate enhancement and suppression observed as functions of cavity frequency.

Quantum interference leads to asymmetric Fano line shapes in reaction rate profiles.

Abstract

Harnessing strong light-matter interactions to control chemical reactions in confined electromagnetic fields offers a promising route toward deepening our understanding of chemical dynamics at the collective quantum-mechanical level, with potential implications for future chemical synthesis paradigms. Achieving this goal, however, requires an in-depth mechanistic understanding of the underlying dynamical processes. As a step in this direction, we present a systematic and numerically exact quantum dynamical study of cooperative reaction dynamics inside an optical microcavity. Using a hierarchy of model systems with increasing complexity, we elucidate how cavity-modified reactivity emerges from-and is highly sensitive to-subtle structural and environmental variations. Our models consist of optically dark reactive molecules, each represented by a symmetric double well potential, coupled to infrared-active non-reactive intramolecular or solvent vibrational modes, as well as their respective dissipative environments. Our results demonstrate that cavity-induced rate modifications arise from a delicate interplay among mode hybridization in strong-coupling regimes, the dynamical balance of all participating energy exchange processes, and quantum interference between multiple fluctuation-dissipation-mediated reaction pathways enabled by collective cavity coupling. By continuously tuning a single system parameter or introducing molecular collectivity, we observe qualitatively distinct rate modification profiles as functions of the cavity frequency, including resonant rate enhancement, resonant rate suppression, hybridization-induced peak splitting, and, notably, asymmetric Fano-type line shapes in which enhancement peaks and suppression dips coexist within a narrow resonance window, highlighting the important role of quantum interference in cavity-modified chemical reactivity.