Cooperative Phenomena in Resonant Electromagnetic Propagation
IBM1
TL;DR: In this paper, it is shown that superradiance can be characterized by a specific maximum cooperation number and associated cooperation time, which are defined for the superradiant state, but their meaning and usefulness can be extended to other situations.
Abstract: Phenomena of coherent resonant propagation can be considered as resulting from the cooperative interaction of a certain number of excited two-level systems. It is shown that these phenomena can be characterized by a specific "maximum cooperation number" and by the associated "cooperation time." These are defined for the superradiant state, but their meaning and usefulness can be extended to other situations. The alternative description of of superradiance as a spontaneous or as a stimulated effect is also discussed and it is shown that with the help of the new concepts, the Dicke quantum perturbative treatment can be reconciled with the semiclassical theories.
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TL;DR: This paper deals with the dynamics of open systems moving irreversibly under the influence of their surroundings (B), and uses a complete microscopic description of the composite system S⊕B as a basis for the discussion of an open system S.
Abstract: This paper deals with the dynamics of open systems (S) moving irreversibly under the influence of their surroundings (B). As a basis for the discussion of an open system S we use a complete microscopic description of the composite system S⊕B. By eliminating the coordinates of B we infer the behavior of S. The motivation for this investigation is that nature frequently confronts us with coupled systems S and B only one of which, say S, is of experimental relevance. It is then a dictate of economy to look for a “closed” description of the dynamics of S alone. Let us mention just three out of the countless examples.
346 citations
TL;DR: In this article, the frequency shifts in emission and absorption arising from resonant many-body interactions in a system of two-level atoms are discussed from several points of view: (1) in the language of superradiance, Dicke states, quantum electrodynamics and perturbation theory, with emphasis on the impact approximation; (2) by means of diagrams related to the temperature-Green's function formalism.
284 citations
TL;DR: In this article, a review of the recent achievements in nonrelativistic quantum electrodynamics, especially nonlinear and coherent phenomena, is presented within simple models in section 1.
205 citations
TL;DR: In this article, the modification of fluorescence lifetimes due to the presence of mirrors is discussed using an image method and the close analogy of this system with that of many-atom cooperative decay is exploited and discussed.
199 citations
TL;DR: It is shown that, at large detuning, the decay rate of the off-axis fluorescence of a large and dilute cloud of cold rubidium atoms after the sudden switch off of a low-intensity laser driving the atomic transition increases with the on-resonance optical depth.
Abstract: Superradiance has been extensively studied in the 1970s and 1980s in the regime of superfluorescence, where a large number of atoms are initially excited. Cooperative scattering in the linear-optics regime, or "single-photon superradiance," has been investigated much more recently, and superradiant decay has also been predicted, even for a spherical sample of large extent and low density, where the distance between atoms is much larger than the wavelength. Here, we demonstrate this effect experimentally by directly measuring the decay rate of the off-axis fluorescence of a large and dilute cloud of cold rubidium atoms after the sudden switch off of a low-intensity laser driving the atomic transition. We show that, at large detuning, the decay rate increases with the on-resonance optical depth. In contrast to forward scattering, the superradiant decay of off-axis fluorescence is suppressed near resonance due to attenuation and multiple-scattering effects.
172 citations