Quantum partial teleportation as optimal cloning at a distance

摘要

We propose a feasible scheme of conditional quantum partial teleportation of a qubit as optimal asymmetric cloning at a distance. In this scheme, Alice preserves one imperfect clone whereas other clone is teleported to Bob. Fidelities of the clones can be simply controlled by an asymmetry in Bell-state measurement. The optimality means that tightest inequality for the fidelities in the asymmetric cloning is saturated. Further we design a conditional teleportation as symmetric optimal N-->N+1 cloning from N Alice's replicas on single distant clone. We shortly discussed two feasible experimental implementations, first one for teleportation of polarization state of a photon and second one for teleportation of a time-bin qubit.