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arXiv · 0807.1657

Quantum Cloning without Interference

Benoit Roubert·Daniel Braun
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Abstract

We study the role of interference in the process of quantum cloning. We show that in order to achieve better than classical cloning of a qubit no interference is needed. In particular, a large class of symmetric universal 1$\to$ 2 qubit cloners exists which achieve the optimal average fidelity 5/6 for such machines, without using any interference. We also obtain optimal average fidelities for interference--free cloning in asymmetric situations, and discuss the relation of the quantum cloners found to the Bu\v{z}ek--Hillery quantum cloner.

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Benoit Roubert, Daniel Braun. 2008-07-10. Quantum Cloning without Interference. https://doi.org/10.1103/physreva.78.042311

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