Suppression and Enhancement of Thermal Chemical Rates in a Cavity

The observed modification of thermal chemical rates in Fabry-Perotcavities remains a poorly understood effect theoretically. Recent breakthroughsexplain some of the observations through the Grote-Hynes theory, where the cavityintroduces friction with the reaction coordinate, thus reducing the transmissioncoefficient and the rate. The regime of rate enhancement, the observed sharpresonances at varying cavity frequencies, and the survival of these effects in thecollective regime remain mostly unexplained. In this Letter, we consider thecis-transisomerization of HONO atomistically using anab initiopotential energysurface. We evaluate the transmission coefficient using the reactiveflux method andidentify the conditions for rate acceleration. In the underdamped, low-frictionregime of the reaction coordinate, the cavity coupling enhances the rate withincreasing coupling strength until reaching the Kramers turnover point. Sharpresonances in this regime are related to cavity-enabled energy redistribution channels

Automated summary

This letter investigates the observed modification of thermal chemical rates in Fabry-Perot cavities and explains the mechanism behind the reduction in transmission coefficient and rate due to friction caused by cavity-reactor coupling. The authors evaluate the transmission coefficient and identify conditions for rate acceleration using an ab initio potential energy surface for the cis-trans isomerization of HONO.