Generation of photon-plasmon quantum states in nonlinear hyperbolic   metamaterials
  We develop a general theoretical framework of integrated paired photon-plasmon generation through spontaneous wave mixing in nonlinear plasmonic and metamaterial nanostructures, rigorously accounting for material dispersion and losses in quantum regime through the electromagnetic Green function. We identify photon-plasmon correlations in layered metal-dielectric structures with 70% internal heralding quantum efficiency, and reveal novel mechanism of broadband generation enhancement due to topological transition in hyperbolic metamaterials. 
Alexander N. Poddubny, Ivan V. Iorsh, and Andrey A. Sukhorukov
cond-mat.mes-hall physics.optics quant-ph