Theory of Polariton Energy Transfer

Recent experiments have remarkably demonstrated distance-independent energy transfer between molecular excitons. This astonishing phenomenon occurs for spatially separated donors and acceptors coupled strongly to optical modes inside a microcavity. Such coupling results in hybrid states whose delocalization among donors, acceptors, and cavity photons allows the states to exchange energy at separation-invariant rates. However, a theoretical model that elucidates the mechanisms of this exchange has yet to be proposed. To address this need, we have developed the first comprehensive theory of polariton energy transfer. Specifically, our formalism describes the energetics of slabs of donor and acceptor molecules strongly coupled to surface plasmons. Application of this theory to cyanine dye J-aggregates affords experimentally consistent mechanistic insights and establishes strong light-matter coupling as a promising avenue for long-range energy transfer.