Generation of an entangled coherent state and reconstruction of a two-mode entangled state via resonant interaction

We present a scheme to prepare two modes of a superconducting cavity in an entangled coherent state. The scheme is based on the resonant interaction of a Λ-configuration three-level atom with two cavity modes and two strong classical laser fields. We also show that the scheme can be employed to directly measure the Wigner characteristic function of the two-mode entangled state in a cavity.