Single photons for quantum information processing

Single photons are attractive carriers of Quantum Information. Once produced, they can be reliably manipulated and can travel long distances unaffected. They are the main constituents of quantum communication protocols, and it is likely that they will even play a major role in the development of quantum computers.; This work presents experimental and theoretical improvements of existing semiconductor quantum dot single photon sources for their application to quantum information. We demonstrate the experimental realization of some basic optical quantum information protocols: entanglement generation and quantum state teleportation. We also develop fabrication and optical characterization techniques for a new type of quantum dot based single photon source, with photonic crystal technology.; Aware of some intrinsic limitations of existing single photon sources, we go on to develop an extensive theory for the coherent control of a single photon pulse using cavity a QED technique. We show how to trap or generate a single photon pulse reversibly in an atom-cavity system under the most general experimental conditions. In particular we show how to realize such processes in a non-adiabatic way and in the cavity QED regime of weak coupling. This technique allows the complete control over a single photon pulse temporal amplitude, and gives the possibility of fast exchange of quantum information in quantum networks. Relying on this technique, we explain how to build the main elements of an all-integrated on-chip quantum computer based on single QD electron spin and single photon exchange via photonic crystal cavities and wave-guides.