  We provide the quantum mechanical description of the excitation of surface
plasmon polaritons on metal surfaces by single-photons. An
attenuated-reflection setup is described for the quantum excitation process in
which we find remarkably efficient photon-to-surface plasmon
wavepacket-transfer. Using a fully quantized treatment of the fields, we
introduce the Hamiltonian for their interaction and study the quantum
statistics during transfer with and without losses in the metal.
