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We present our model to teleport an unknown quantum state using entanglement between two distant parties. Our model takes into account experimental limitations due to contribution of multi-photon pair production of parametric down conversion source, inefficiency, dark counts of detectors, and channel losses. We use a linear optics setup for quantum teleportation of an unknown quantum state by the sender performing a Bell state measurement. Our theory successfully provides a model for experimentalists to optimize the fidelity by adjusting the experimental parameters. We apply our model to a recent experiment on quantum teleportation and the results obtained by our model are in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

Abstract: A single quantum dot embedded in a photonic crystal defect cavity allows for the investigation of cavity quantum electrodynamics effects in a solid-state environment. We present experiments demonstrating the quantum nature of this fundamental system in the strong coupling regime. Photon correlation measurements are used to characterize the fundamental properties of this unique system: through these experiments, we identify an unexpected, efficient sustaining mechanism that ensures strong cavity emission and is quantum correlated with the exciton resonance, even when all the quantum dot resonances are far detuned from the cavity mode. To cite this article: A. Badolato et al., C. R. Physique 9 (2008). [Copyright &y& Elsevier]

Abstract: We report on semiconductor waveguides for room-temperature parametric fluorescence in the near infrared. Two phase-matching schemes are presented: form birefringence and counter-propagating phase matching. The characteristics and performances of these solutions are discussed and compared for different kinds of applications. The emergence of these devices opens new perspectives toward guided-wave parametric amplifiers, oscillators, and sources for quantum information. To cite this article: M. Ravaro et al., C. R. Physique 8 (2007). [Copyright &y& Elsevier]

Abstract: A selection of optical experiments is presented, demonstrating the utility of semiconductors in two novel areas of research: spintronics and quantum information. First we show examples of spin manipulation in semiconductor quantum wells. The light is used to generate a spin polarization and to detect it. Next we discuss application of optical methods in studies of carrier-induced ferromagnetism in quantum wells. Finally, we present examples of single quantum dot spectroscopy related to perspectives of application of quantum dots in quantum information, and, in particular, the use of photon correlation measurements as a tool to study the quantum dot excitation mechanisms. To cite this article: J.A. Gaj et al., C. R. Physique 8 (2007). [Copyright &y& Elsevier]

A large number of scientific proposals in recent years are based on transport and manipulation of information using single quantum objects. Although very impressive theoretical perspectives have been envisaged, experimental demonstrations are still limited due to technological difficulties with present state-of-the-art devices. This paper presents various approaches aiming at efficient single or twin photons semiconductor sources. The emergence of these devices will be an important technological breakthrough in the field of quantum information. To cite this article: V. Berger, J.-M. Ge´rard, C. R. Physique 4 (2003). [Copyright &y& Elsevier]