Entanglement generation with coherent states using cross-Kerr nonlinearity

We propose methods for generating Bell-type entangled coherent states for quantum information processing. The protocols are completed using linear optical elements, single-photon detectors, and cross-Kerr nonlinearity. We investigate the decoherence effect on our protocols; photon loss is found to affect only the probability, not the fidelity, of the generation process. The entanglement of the generated entangled states is also analyzed using concurrence. Finally, the feasibility of our scheme is discussed using the continuous-time cross-phase modulation model. In the weak nonlinearity region, on the condition that theta(2)vertical bar alpha(p)vertical bar(2) similar to 1, theta << 1, and sigma(2) << 1, our scheme is applicable theoretically. (C) 2013 Optical Society of America