Theory for Cavity-Modified Ground-State Reactivities via Electron-Photon Interactions

We provide a simple and intuitive theory to explain howcouplinga molecule to an optical cavity can modify ground-state chemical reactivityby exploiting intrinsic quantum behaviors of light-matter interactions.Using the recently developed polarized Fock states representation,we demonstrate that the change of the ground-state potential is achieveddue to the scaling of diabatic electronic couplings with the overlapof the polarized Fock states. Our theory predicts that for a proton-transfermodel system, the ground-state barrier height can be modified throughlight-matter interactions when the cavity frequency is in theelectronic excitation range. Our simple theory explains several recentcomputational investigations that discovered the same effect. We furtherdemonstrate that under the deep strong coupling limit of the lightand matter, the polaritonic ground and first excited eigenstates becomethe Mulliken-Hush diabatic states, which are the eigenstatesof the dipole operator. This work provides a simple but powerful theoreticalframework to understand how strong coupling between the molecule andthe cavity can modify ground-state reactivities.