Generation of four-particle GHZ states in bimodal cavity QED

We propose a scheme for preparing four-particle Greenberger--Horne--Zeilinger states using two identical bimodal cavities, each supports two modes with different frequencies. This scheme is an alternative to another published work Christopher C Gerry 1996 Phys. Rev. A 53 4591. Comparisons between them are discussed. The fidelity and the probability of success influenced by cavity decay for the generated states are also considered.