Conditional implementation of an asymmetrical universal quantum cloning machine
Radim Filip · Physical Review A · 2004
We propose two feasible experimental implementations of an optimal asymmetric $1\ensuremath{\rightarrow}2$ quantum cloning of a polarization state of photon. Both implementations are based on a partial and optimal reverse of recent conditional symmetrical quantum cloning experiments. The reversion procedure is performed only by a local measurement of one from the clones and ancilla followed by a local operation on the other clone. The local measurement consists only of a single unbalanced beam splitter followed in one output by a single-photon detector and the asymmetry of fidelities in the cloning is controlled by a reflectivity of the beam splitter.