Atomic and Nuclear Physics

Biography

Biography: Nicolae A Enaki

Abstract

It is investigated the application of coherent emission of two subgroups of quanta obtained in the cooperative decay of excited enable of radiator (nuclei, atoms or molecules) mixture, so that correlation appears between the blocks of quanta belonging to diff erent modes of the electromagnetic field. It is proposed the new eff ect, in which the two-quantum cooperative emission is established between the two sub-ensemble of excited radiators (see Fig. 1 A and B). Th e equidistant two-level sub-ensemble, excited relative the dipole forbidden transition, can be ignited in two-quantum super radiance regime by single-photon decay process of dipole active species of radiators. We chose the situation in which the one-photon Dicke cooperative emission is inhibited by large emission band of the dipole active sub-ensemble. In this situation the new three particle exchange integrals between the dipole forbidden and dipole active sub-ensembles drastically increases. So the cooperative emission of the dipoleforbidden sub-ensemble of atoms stimulates the two-quantum emission of dipole-active species of radiators. This cooperative process between the dipole-forbidden radiators and dipole-active sub-ensemble is accompanied by the establishment of the coherence between the photon pairs. The multi-mode broadband light can be reduced to the coherent states of the bimodal ensemble of the electromagnetic fi eld. Th e method of recording of information from such a coherent fi eld opens the new perspectives in stimulation gamma emission, quantum cryptography and quantum information. At the first glance, one observes that such coherent effects may have nothing new in comparison with the traditional one- photon coherence. But the two-quantum coherent beam may be destroyed or restored if the photon-pair pulses pass through a disperse medium. So the ”idler” photons from each pair change their directions relative to ”signal” photons. Focusing the ”signal” and ”idler” photons into diff erent optical fi bers, we can destroy the coherence among the bi-photons. However, aft er a certain propagation distance, the ”idler” and ”signal” photons from the pairs may be mixed again and we may observe, that the restoration of coherence propriety of the bimodal fi eld.