Scheme for assisted cloning an unknown arbitrary three-qubit state.

We present a scheme for perfect cloning or orthogonal complementing an unknown arbitrary three-qubit state with assistance. This cloning scheme is divided into two stages. In the first stage, the initial state can be teleported from a sender to a receiver probabilistically via three partially entangled states. In the second stage, the exact copying and orthogonal complementing of the three-qubit state can be created with unity fidelity in a probabilistic manner with the state preparer performing an appropriate tri-particle projective measurement. It is shown that for some special ensembles of the three-qubit state our assisted cloning scheme can be achieved exactly and deterministically. [ABSTRACT FROM AUTHOR]