Generating correlated two-mode states via the resonant interaction of Ξ-type atoms with a two-mode field

A scheme for preparing correlated two-mode states is presented. It is based on the detection of a sequence of suitably prepared three-level Ξ-type atoms in the lowest level after they resonant interaction with a two-mode cavity field. As a typical example, we show how to generate four-dimensional maximally entangled state.