  We show the existence of virtual polarization states during the interaction
of modes in metasurface stacks. In support of our findings we experimentally
realize a metasurface stack, consisting of an isotropic layer of nano-patches
and an anisotropic layer of nano-wires. Utilizing an analogy to the interaction
of electrons at junctions in mesoscopic electron transport via Feynman paths,
we present a semi-analytical description of the modal interaction inside this
stack. We then derive a series of all possible reflection paths light can take
inside the metasurface stack.
