Coupling semiconductor nanocrystals to high-Q silica microspheres: cavity QED of quantum dots

Summary form only given. We have developed a novel QD microcavity by coupling core/shell semiconductor nanocrystals resonantly to whispering gallery modes (WGMs) of a silica microsphere. We have shown that this composite microcavity system features a photon lifetime of order 0.1 Js, corresponding to Q-factors of order 10/sup 8/, four to five orders of magnitude greater than that of other semiconductor microcavities. The extremely high-Q factors along with the very small mode volume allow us to achieve for the first time to our knowledge the good cavity limit of cavity QED of QDs, thus providing a model system for investigating effects of quantum transitions and decoherence in single QDs.