Multichromophore excitons and resonance energy transfer: Molecular quantum electrodynamics

Resonance energy transfer in multichromophore arrays, such as light-harvesting complexes and dendrimers, is well documented. The theory involved in the migration of energy to an acceptor from one excited donor, or concertedly from two of three such donors, has also been thoroughly investigated. In cases where the initial excitations form a delocalized exciton amongst the donors the corresponding theory describing transfer to an acceptor is less well-developed. By considering a model dendrimeric system we analyze the configuration and energy transfer properties of excitonic states formed by the absorption of one and two photons. Using molecular quantum electrodynamics and interaction-pair notation we quantify these effects in terms of quantum amplitudes. New insights result from our description in terms of state sequences. In particular it is possible for the first time to identify quantum interconnections between different exciton relaxation routes