Light scattering from a dense and ultracold atomic gas

The quantum optical response of high-density ultracold atomic systems is important to a wide range of fundamentally and technically important physical processes. We present here a microscopic analysis of the light scattering on such a system and compare it with a corresponding description based on macroscopic Maxwell theory. Results are discussed in the context of the spectral resonance structure of the scattering cross section, the time-dependent response under a range of conditions, and evolution of these quantities as the atomic density is varied. For high atomic densities, the microscopic theoretical treatment reveals a distributed and configuration-dependent narrow resonance structure. This structure is attributed to microcavity spatial structures associated with the dense and ultracold atomic gases.