Non-local effects in effective medium response of nano-layered meta-materials

We analyze electromagnetic modes in multi-layered nano-composites and demonstrate that the response of a majority of realistic layered structures is strongly affected by the non-local effects originating from strong field oscillations across the system, and is not described by conventional effective-medium theories. We develop the analytical description of the relevant phenomena and confirm our results with numerical solutions of Maxwell equations. Finally, we use the developed formalism to demonstrate that multi-layered plasmonic nanostructures support high-index volume modes, confined to deep subwavelength areas, opening a wide class of applications in nanoscale light management.