Exciton-Condensate-Like Amplification of Energy Transport in Light Harvesting

Bose-Einstein condensation of excitons, in which excitons condense into a single coherent quantum state, known as an exciton condensate, enables frictionless energy transfer, but typically occurs under extreme conditions in highly ordered materials, such as graphene double layers. In contrast, photosynthetic light-harvesting complexes demonstrate extremely efficient transfer of energy in disordered systems under ambient conditions. Here, we establish a link between the two phenomena by investigating the potential for exciton-condensate-like amplification of energy transport in room-temperature light harvesting. Using a model of the Fenna-Matthews-Olson complex and accounting for intrachromophore electron correlation explicitly through the addition of multiple sites to the individual chromophores, we observe amplification of the exciton population in the particle-hole reduced density matrix through an exciton-condensate-like mechanism. The exciton-condensate-like amplification evolves with the dynamics of exciton transfer, and the nature of amplification is influenced by intra- and interchromophore entanglement, as well as the initial excitation model and number of sites per chromophore. Tuning intrachromophore coupling also increases the rate of exciton transfer with a maximum enhancement of nearly 100%. The research provides fundamental connections between exciton condensation and exciton transport in light-harvesting complexes with potential applications for harnessing the exciton-condensate-like mechanism to enhance energy transfer in synthetic systems and create new materials capable of highly efficient energy transfer.