PHOTON-NUMBER-STATE GENERATION WITH A SINGLE 2-LEVEL ATOM IN A CAVITY- A PROPOSAL

A single two-level atom can be used to prepare an arbitrary photon num ber state (Fock state) in a high Q cavity. The atom undergoes a contro lled succession of interactions with two cavity modes. One of them con tains a coherent field. The atom transfers photons one by one from thi s field to the initially empty second mode. The scheme can be extended to prepare a quantum superposition of the vacuum with a Fock state, a highly non-classical situation. We discuss the feasibility of the exp eriment with our present Rydberg-atom cavity QED set-up.