Generating N00N-states of surface plasmon-polariton pairs in a nonlinear nanoparticle on metallic substrate

We study the generation of surface plasmon-polariton pairs with a gallium arsenide nanoparticle located at the silver-air interface. We demonstrate theoretically that N00N-states of surface plasmon-polariton pairs with N=2 can be obtained for certain excitation geometries. The effect can be physically interpreted as the result of a quantum interference between pairs of induced sources, each emitting either signal or idler plasmons.