Complete N-photon Greenberger-Horne-Zeilinger-state analyzer and its applications to quantum communication

We propose a scheme to completely identify N-photon Greenberger-Horne-Zeilinger (GHZ) states based on the method of disentanglement with the cross-phase modulation (XPM) taking place in cross-Kerr medium between two single-photon pulses. The main idea of the scheme is also appropriate for other physical systems; hence we give the universal disentangling matrix for N-particle GHZ states. Using the present GHZ-state analyzer, we achieve the preparation of multiparticle GHZ states, quantum dense coding, and teleportation. All of these tasks are deterministic in ideal case, which is discussed in the paper. (C) 2011 Elsevier B.V. All rights reserved.