Enhanced superradiance from a slab of resonant atoms sandwiched between two noble metal plates

I compute the Fabry–Perot plasmonic resonance eigenfrequencies for a system consisting of two noble metal parallel plates as function of the distance between the plates. Then, I show that the superradiance rate from an ensemble of two level-atoms placed between the two plates is enhanced when the atomic resonance frequency corresponds to one of the plasmonic resonance frequencies of the passive (cold) parallel-plates system of the same configuration.