Water decomposition equilibrium under vibrational strong and ultrastrong coupling

Pioneering experimental results have shown chemical equilibrium can be shifted significantly inside an optical cavity. The formation of hybrid states of light and matter (polaritons) and weakly coupled modes (dark states) has been argued to be the main contributor to the observed changes, but the mechanistic understanding is lacking. In this presentation, we will describe the main findings of our recent studies of (single-mode) microcavity effects on chemical equilibrium. We theoretically investigated the waterdecomposition reaction under strong and ultrastrong coupling conditions and found that the equilibrium constant can be enhanced or suppressed under distinct scenarios. Connections to recent experiments and future challenges will be highlighted.