Chemistry Meets Plasmon Polaritons and Cavity Photons

Macroscopic quantum electrodynamics (macroscopic QED) provides a unified framework that integrates the continuum of photonic modes and realistic dielectric environments into molecular systems, offering a comprehensive approach to exploring QED phenomena in chemistry. First, we develop a generalized theory of molecular fluorescence that delivers parameter-free predictions from weak to strong light–matter coupling regimes. Second, we extend resonance energy transfer theory to include both electromagnetic retardation and dielectric responses, yielding improved descriptions of energy transfer mediated by plasmon polaritons and cavity photons. Third, we formulate a unified electron-transfer theory that bridges radiative and non-radiative processes, extend Marcus theory, and demonstrate a wide-dynamic-range control of electron-transfer reactions in the weak-coupling regime. Fourth, we investigate multiple molecules coupled to plasmon polaritons and uncover anomalous giant superradiance that lies beyond the Dicke model. Fifth, we generalize the Born-Huang expansion within the macroscopic QED framework and reveal non-adiabatic QED effects such as non-adiabatic emission, providing insights into QED-driven processes. These advances connect quantum optics, nanophotonics, and chemical physics, offering predictive tools for experimental and theoretical studies on QED chemistry.