Quantum theory of surface-plasmon polariton scattering

We introduce the quantum mechanical formalism for treating surface plasmon polariton scattering at an interface. Our developed theory—which differs fundamentally from the analogous photonic scenario—is used to investigate the possibility of plasmonic beam splitters at the quantum level. Remarkably, we find that a wide range of splitting ratios can be reached. As an application, we characterize a 50:50 plasmonic beam splitter and investigate first-order quantum interference of surface plasmon polaritons. The results of this theoretical study show that surface plasmon beam splitters are able to reliably and efficiently operate in the quantum domain. ©2010 The American Physical Society