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Parametric Emission (parametric + emission)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

Polariton correlation in microcavities produced by parametric scattering

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 11 2005
Wolfgang Langbein
Abstract The spontaneous and self-stimulated parametric emission from a semiconductor microcavity after resonant pulsed excitation is measured. The emission of the lower polariton branch is resolved in two-dimensional momentum space, using either time-resolved or spectrally resolved detection. The polariton,polariton scattering dynamics is generally in good agreement with the theory using the nonlinearity due to the excitonic part and the dispersion due to the photonic part of the polariton. The peculiar figure-8 shaped distribution in momentum space of the final states of the parametric scattering is observed. Renormalization of the dispersion due to the bound biexciton state is found to influence the final state distribution. Using two pump directions the shape of the final state distribution can be changed to a peanut or oval for the mixed parametric processes. In this dual pump configuration, we find that polaritons in two distinct idler-modes interfere if and only if they share the same signal-mode, showing the existence of polariton pair correlations that store the "which-way" information. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Entanglement and parametric dynamics in quantum optics with interacting polaritons

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2008
S. Portolan
Abstract We report on a microscopic investigation of the polariton parametric emission in the presence of coherent and incoherent interaction processes by means of a full quantum description based on a nonequilibrium quantum Langevin approach for open systems applied to interacting-electron complexes described within the dynamics controlled truncation scheme. It provides an easy recipe to calculate multi-time correlation functions which are key-quantities in quantum optics. In particular we report on calculations of polariton intensities (i.e. single time correlators) and spectra (i.e. two times correlators). We apply our scheme to a two-pumps set-up in microcavity recently proposed showing a quantitative analysis of the quantum correlation properties of the emitted photons. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Polariton entanglement in the self-stimulated regime

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2006
S. Portolan
Abstract We investigate the influence of environmental noise on polariton entangled pairs in the self-stimulated regime. By adopting a recent separability criterion, we show that self-stimulation may suppress the detrimental influence of noise on entanglement, but once effective, a noise-equipped classical model of parametric emission provides the same results of quantum theory with respect to the separability criterion. More generally we show that, in the macroscopic limit, it is not possible to observe violations of local realism with measurements of finite order n -particle correlations only. These results provide a prototypical case of the emergence of macroscopic local realism in the presence of strong entanglement even in the absence of decoherence. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Influence of the phonon-exciton interaction on exciton-exciton quantum correlation in semiconductor microcavities

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2006
S. Portolan
Abstract We present an extension of the previous descriptions based on the Dynamics Controlled Truncation Scheme of light-matter interaction beyond mean-field, including the microscopic description of the exciton-photon interaction. This enables the microscopic analysis of the influence of decoherence and noise on the polariton quantum correlations originating from nonlinear optical processes. We expand the operators involved in the dynamics in terms of exact eigenstates of the electron system, the photon and phonon operators and treat phonon-assisted transitions within the Markov approximation. In particular, we present quantum Heisenberg-Langevin equations describing light-induced excitations in semiconductor systems interacting with the phonon bath. This theoretical framework is applied to study the influence of dephasing and noise due to photoluminescence on polariton quantum correlations generated by parametric emission in microcavities. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]