Superradiance from an ultrathin film of three-level V -type atoms: Interplay between splitting, quantum coherence and local-field effects

We carry out a theoretical study of the collective spontaneous emission (superradiance) from an ultrathin film comprised of three-level atoms with V configuration of the operating transitions. As the thickness of the system is small compared to the emission wavelength inside the film, the local-field correction to the averaged Maxwell field is relevant. We show that the interplay between the lowfrequency quantum coherence within the subspace of the upper doublet states and the local-field correction may drastically affect the branching ratio of the operating transitions. This effect may be used for controlling the emission process by varying the doublet splitting and the amount of low-frequency coherence. PACS numbers: 42.50.Fx, 42.50.Md Submitted to: J. Opt. B: Quantum Semiclass. Opt. § On leave from ”S.I. Vavilov State Optical Institute”, Birzhevaya Linia 12, 199034 Saint-Petersburg, Russia Superradiance from an ultrathin film of three-level V -type atoms 2