Tunable radiation enhancement and suppression using a pair of photonically doped epsilon-near-zero (ENZ) slabs

Manipulation of the radiation efficiency and pattern of quantum emitters by engineering the electromagnetic properties of the surrounding medium is crucial for designing various light sources. Here, we theoretically demonstrate the possibility of designing a compact and tunable resonator using a pair of photonically doped epsilon-near-zero (ENZ) slabs that are separated by a deeply subwavelength air gap. Such resonators are shown to be capable of switching between completely transparent and opaque states, for a TM-polarized normally incident plane wave, by slightly changing the permittivity of the dielectric dopants. We exploit this behavior for tunable radiation enhancement and suppression for a quantum emitter placed inside the air gap.