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

Abstract

Superradiance from an ultrathin film of three-level V -type atoms: Interplay between splitting, quantum coherence and local-field effects Abstract.We carry out a theoretical study of the collective spontaneous emission (superradiance) from an ultrathin film comprised of three-level atoms with Vconfiguration 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.

Coherent responses of the resonance atom layer to short optical pulse excitation

“…The solid curve exhibits the anticipated reflection of a weak pulse (17). The transient regime ( =1.5) is featured by the oscillation of the transmittivity (Fig.…”

“…Thus, a specific spatial synchronism of photon echo generated by a thin resonance layer on an interface was considered in 14 . The approaches worked out for conventional models were extended to another low dimension system, such as the layer of quantum dots 15 , film of three level atoms 16,17 or thin film resonators filled with two-level medium 18 , and another type of resonance, for instance, the two-photon resonance 19,20 The purpose of this work is to demonstrate by numerical modeling, how a thin layer attributes, such as local field effect, a very small thickness of the film, the inhomogeneous broadening of resonance transition and even the dispersion of substrate material (Section 1) can affect the transmittance of layer and the temporal shape of transmitted ultra-short pulses (Section 2), including the observation of the photon echo effect 6,21,22 (Section 3). It turned out that Lorentz field correction plays important role in film structures, causing spectral dynamical shifts of atomic system observable in strong coherent coupling of pulsed radiation with a film.…”

Gain without population inversion in a yoked superfluorescence scheme

“…Then Eqs. (16) and (17) yield for the forward direction ab (t,z) = (0) ab δ(z − ct) + (0) ab e − (t−z/c) ξ 1 + η bc n bc ζ…”

“…In particular, it can lead to superfluorescence without inversion [16][17][18][19][20]. In such systems coherence created by a driving field on one transition influences superfluorescence on another transition.…”

Inversionless Superradiance and the Duffing Model

“…In this case, the transition from the upper level to this superposition state appears to be inverted at an arbitrarily small population of the upper level. The initial coherent state of the doublet can be created by a short low-frequency -pulse [22][23][24][25][26][27][31][32][33][34][35][36]. Systems of this kind can be realized in crystals, e.g., in a matrix doped with praseodymium ions [27][28][29][30], the ground state of which has a fine structure.…”