Berry's phase in cavity QED: Proposal for observing an effect of field quantization

A feasible experiment was proposed to investigate quantum effects in geometric phases, arising when a classical source drives not a single quantum system, but two interacting ones. The study shows how to observe a signature of the quantization of the electromagnetic field through a vacuum effect in Berry's phase. The interaction of an atom and a quantized cavity mode altogether driven by an external quasiclassical field is described