Quantum optics in semiconductor microcavities

Polaritons in semiconductor microcavities are hybrid quasi particles consisting of a superposition of cavity photons and two-dimensional excitons in embedded quantum wells (QWs). Owing to their exciton content, they have a strong mutual interaction which can be exploited for producing spontaneous parametric scattering of pump polaritons into signal-idler polariton pairs. This process is able to produce polariton states exhibiting quantum correlations, and can thus be exploited for potential applications as well as to study quantum optical processes within a complex many-body system. Here we present an overview of polariton parametric processes within a full quantum description based on the dynamics controlled truncation scheme. We also describe the results of an experiment that proves the existence of polariton pair correlations. This interpretation is confirmed by a microscopic theoretical analysis of the measured interference visibility. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.