Insights into the mechanisms of optical cavity-modified ground-state chemical reactions.

This article systematically investigates the mechanisms by which vibrational strong coupling inside an optical cavity modifies ground-state chemical reaction rates. Using a symmetric double-well molecular potential and a numerically exact open quantum system approach combining hierarchical equations of motion (HEOM) with matrix product state/tensor train (MPS/TT) methods, the study reveals that resonance peaks in the cavity frequency-dependent reaction rate arise when the cavity photon energy matches molecular vibrational transitions. These peaks result from cavity-induced intramolecular cotunneling pathways fueled by the cavity photon bath, with kinetic factors such as transition probabilities and tunneling rates determining peak intensities. Extending beyond single molecules, the work shows that two identical molecules coupled to the same cavity mode exhibit further rate enhancement via cavity-mediated intermolecular reaction channels, an effect robust to dipole orientation but absent in heterodimers with mismatched vibrational frequencies. The findings highlight the interplay of energetic resonance, kinetic accessibility, and collective coupling in cavity-modified chemical reactivity, providing a foundation for understanding and controlling reactions in polaritonic chemistry.