Realization of a general quantum cloning machine via cavity-assisted interaction

We present a scheme to realize a general quantum cloning machine via cavity-assisted interaction. First, this scheme can prepare entangled states of three remote trapped atoms including the W state and the GHZ state. Based on this approach, the quantum information carried by a photon pulse or a trapped atom can be copied to other two trapped atoms. According to the known information of the initial state, the equipment can provide the optimal symmetric (asymmetric) universal and phase-covariant quantum cloning. Further, via the cavity input-output process, the quantum cloning can be realized with high fidelity, even if the atom is not localized in the Lamb-Dicke regime. Copyright (C) EPLA, 2012