Synchronization of N coupled dipoles: From Anderson to Dicke

Summary form only given. The quest for Anderson localization of light is at the center of many experimental and theoretical activities. Cold atoms have emerged as interesting quantum system to study coherent transport properties of light. Initial experiments have established that dilute samples with large optical thickness allow studying weak localization of light [1]. The goal of our research is to study coherent transport of photons in dense samples. One important aspect is the quest of Anderson localization of light with cold atoms and its relation to Dicke super- or subradiance, in particular with large and dense samples of cold atoms.In this talk I will show that Dicke type cooperativity with global synchronization dominates over Anderson localisation with local interferences [2-4], even for high densities of atoms fulfilling the Ioffe-Regel criterion kl<;1. I will show that the standard approach using single parameter scaling theory does not apply for photons in resonant systems and highlight this considering on-resonance scattering of light by cold atoms.