Quantum coherence in vibrational polaritons; reactivity, cooperativity, and molecular coupling
Jianshu Cao Department of Chemistry, MIT
The strong light-matter interaction opens new possibilities of quantum control, but also presents new challenges. Inspired by recent experiments and numerical simulations, we are working on four theory projects: (1) Floquet theory, (2) photon counting statistics, (3) disordered polaritons, and (4) vibrational polariton chemistry. In this talk, I will first summarize the four projects and then focus on our recent efforts to understand coherent vibrational polariton dynamics in the vibrational strong coupling (VSC) regime.
Our quantum transition state theory (TST) calculation  attributes the VSC modification of reaction rates to vibrational frequency shifts in the reactive well and reactive barriers. The vibrational perturbation analysis predicts the dependences of reactivities on temperature, cavity frequency, and light-matter coupling strength. In comparison, application of the generalized resonance energy transfer (gRET) theory  explains the resonant and cooperative effects in vibrational energy relaxation in cavities, as shown in recent simulations. Though the two papers reveal complimentary perspectives of VSC polariton dynamics, new mechanisms  are needed to explore the broad range of intriguing phenomena reported in the VSC regime.
 Yang and Cao, JPC Lett 11, 7204 (2021) Quantum Effects in Chemical Reactions under Polaritonic Vibrational Strong Coupling
 Cao, JPC Lett 13, 10963 (2022) Generalized Resonance Energy Transfer Theory: Applications to Vibrational Energy Flow in Optical Cavities
 Cao and Pollak (in preparation)