Polariton Mediated Electron Transfer via Cavity Quantum Electrodynamics

We investigate the polariton mediated electron transfer reaction in a model system. With analytic rate constant expression and direct quantum dynamical simulations, we demonstrate that charge transfer reactions can be significantly enhanced or suppressed by coupling the molecular system to the quantized radiation field inside an optical cavity. This is due to the fact that quantum light-matter interactions can mediate the effective driving force and electronic couplings between the hybrid light-matter excitation (so-called the polariton states). Under a resonance condition, the effective driving force can be tuned by changing the light-matter coupling strength; for an off-resonant condition, the same effect can be accomplished by changing the molecule-cavity detuning. Forming polaritons thus provides new possibilities to control the fundamental photo-redox chemistry. Further, we find that both the counter-rotating terms and the dipole self-energy in the quantum electrodynamics Hamiltonian play a crucial role for obtaining an accurate polariton eigenenergy and the polariton mediated charge transfer rate constant, especially in the ultra-strong coupling regime. These investigations significantly complement the previous theoretical developments that ignore both terms, and bring interesting concepts from quantum optics into the field of photochemistry