  We show the transition from a fully quantized interaction to a semiclassical
one in entangled small number quantum systems using the quantum trajectories
approach. In particular, we simulate the microwave Ramsey zones used in Rydberg
atom interferometry, filling in the gap between the strongly entangling Jaynes
Cummings evolution and the semiclassical rotation of the atomic internal
states. We also correlate the information flowing with leaking photons to the
entanglement generation between cavity field and flying atom and detail the
roles played by the strong dissipation and the external driving force in
preserving atomic coherence through the interaction.
