Quantum Optics

Ensembles of trapped atoms are almost perfectly isolated from the environment, and their coherent quantum evolution can be probed in detail on experimentally accessible time scales. The tunability of parameters like interaction strength, temperature, density, and dimensionality supported by powerful manipulation techniques allows the realization of many different relevant physical situations. Moreover, the process of absorption and “collective” emission of photons by a set of several atoms is at the heart of several emerging physical phenomena, particularly in the field of quantum information in its various aspects. One of the main challenges in the quest for an efficient distribution of quantum states is to achieve consistent control of the light-atom interaction at the single- photon scale. Hence, the growing interest in investigating the properties of light transport in weakly excited atomic media, the applications of which are of growing importance in several fields: quantum information, quantum simulation, and even cosmology. Clouds of cold atoms subjected to a light field of low intensity are an ideal tool for such investigations.