  We study cooperative effects in energy transfer (ET) from an ensemble of
donors to an acceptor near a plasmonic nanostructure. We demonstrate that in
cooperative regime ET takes place from plasmonic superradiant and subradiant
states rather than from individual donors leading to a significant increase of
ET efficiency. The cooperative amplification of ET relies on the large coupling
of superradiant states to external fields and on the slow decay rate of
subradiant states. We show that superradiant and subradiant ET mechanisms are
efficient in different energy domains and therefore can be utilized
independently. We present numerical results demonstrating the amplification
effect for a layer of donors and an acceptor on a spherical plasmonic
nanoparticle.
