Enhanced Faraday rotation via resonant tunnelling in tri-layers containing magneto-optical metals

We study resonant tunnelling effects that can occur in trilayer structures featuring a dielectric layer sandwiched between two magneto-optical(MO)-metal layers. We show that the resonance splitting associated with these phenomena can be exploited to enhance Faraday rotation at optical frequencies. Our results indicate that, in the presence of realistic loss levels, a tri-layer structure of subwavelength thickness is capable of yielding sensible (∼10°) Faraday rotation with transmittance levels that are an order of magnitude larger than those attainable with a standalone slab of MO metal of the same thickness.