  The theory of energy transfer dynamics of a pair of donor and acceptor
molecules located in the plasmonic hot spots is developed by means of the
master equation approach and the electromagnetic Green's tensor technique. A
nonlocal effect has been considered by using a hydrodynamic model. The coherent
interaction between the two molecules in plasmonic nanostructures is
investigated under some strong coupling conditions. It is shown that the energy
transfer efficiency of a pair of molecules can be improved largely and the
transfer time decreases to dozens of femtoseconds when the contribution of
quantum coherence is considered. The physical origin for such a phenomenon has
also been analyzed. This ultrafast and high-efficiency energy transfer
mechanism could be beneficial for artificial light-harvesting devices.
