Charge-Transfer Chemical Reactions in Nanofluidic Fabry-P{\'e}rot Cavities

TL;DR

This paper explores how strong light-matter interactions in nanofluidic Fabry-Pérot cavities influence chemical reaction kinetics, revealing optically tunable reaction parameters and measurable ultrafast dynamics despite losses.

Contribution

It introduces the concept of 'reacton' as a polariton dressed by environmental excitations and demonstrates its role in modulating chemical reaction kinetics within optical cavities.

Findings

Reacton formation modifies reaction kinetics.

Optical parameters influence reaction driving-force and reorganization energy.

Measurable ultrafast signatures predicted in pump-probe experiments.

Abstract

We investigate the chemical reactivity of molecular populations confined inside a nanofluidic Fabry-P{\'e}rot cavity. Due to strong light-matter interactions developing between a resonant electromagnetic cavity-mode and the electric dipole moment of the confined molecules, a polariton is formed. The former gets dressed by environmental vibrational and rotational degrees of freedom of the solvent. We call the resulting polariton dressed by its cloud of environmental excitation a ''reacton'', since it further undergoes chemical reactions. We characterize how the reacton formation modifies the kinetics of a photoisomerization chemical reaction involving an elementary charge-transfer process. We show that the reaction driving-force and reorganization energy are both modulated optically by the reactant concentration, the vacuum Rabi splitting and the de-tuning between the Fabry-P{\'e}rot cavity frequency and targeted electronic transition. Finally, we compute the ultrafast picosecond dynamics of the whole photochemical reaction. We predict that despite optical cavity losses and solvent-mediated non-radiative relaxation, measurable signatures of the reacton formation can be found in state-of-the-art pump-probe experiments.