Chefles, Anthony and Barnett, Stephen M.
(1999)
*Strategies and networks for state-dependent quantum cloning.*
Physical Review A, 60 (1).
pp. 136-144.
ISSN 1050-2947

## Abstract

State-dependent cloning machines that have so far been considered either deterministically copy a set of states approximately or probablistically copy them exactly. In considering the case of two equiprobable pure states, we derive the maximum global fidelity of N approximate clones given M initial exact copies, where N>M. We also consider strategies that interpolate between approximate and exact cloning. A tight inequality is obtained that expresses a trade-off between the global fidelity and success probability. This inequality is found to tend, in the limit N → ∞, to a known inequality that expresses the trade-off between error and inconclusive result probabilities for state-discrimination measurements. Quantum-computational networks are also constructed for the kinds of cloning machine we describe. For this purpose, we introduce two gates: the distinguishability transfer and state separation gates. Their key properties are described and we show how they may be decomposed into basic operations.

Item type: | Article |
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ID code: | 5859 |

Keywords: | quantum cloning, quantum physics, optics, Optics. Light, Atomic and Molecular Physics, and Optics |

Subjects: | Science > Physics > Optics. Light |

Department: | Unknown Department Faculty of Science > Physics |

Depositing user: | Miss Darcy Spiller |

Date Deposited: | 30 Apr 2008 |

Last modified: | 20 Oct 2015 11:50 |

URI: | http://strathprints.strath.ac.uk/id/eprint/5859 |

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