Schemes for Greenberger-Horne-Zeilinger and cluster state preparation

Schemes to generate Greenberger-Horne-Zeilinger (GHZ) and cluster states of three atoms are proposed in a two-mode cavity. The advantages of the schemes are their robustness against decoherence due to spontaneous emission of the excited states and decay of the cavity modes. Moreover, the schemes can be generalized to generate N-atom entangled states.