Cavity-Mediated Enhancement of the Energy Transfer in the Reduced Fenna–Matthews–Olson Complex

The formation of hybrid light-matter states (polaritons) is known to change the course of dynamics in a chemical reaction. In the current study, we explore this effect of polariton formation on the sub-process of energy transfer in photosynthesis theoretically. The Fenna-Mathews-Olson (FMO) complex is a molecular wire responsible for energy transfer in the green-sulfur bacteria. We consider the three essential sites of the FMO complex (arranged in different ways) confined in a cavity that resonates with one of the sites. The numerically exact HEOM method is employed to simulate the system. The coupling to the cavity is varied, and the system is gradually taken to the strong light-matter coupling. Our findings reveal that strong light-matter interactions can enhance the rate of population transfer. However, this comes with a trade-off of reduced efficiency compared to cavity-free conditions. The careful analysis reveals new energy transfer pathways forming after forming polaritons. These insights underscore both the potential and limitations of tuning energy transfer in highly efficient natural light-harvesting systems, paving the way for future innovations in bioengineering and artificial systems.