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Telecloning and multiuser quantum channels for continuous variables

P. van Loock·Samuel L. Braunstein
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Abstract

We propose entangled (M+1)-mode quantum states as a multiuser quantum channel for continuous-variable communication. Arbitrary quantum states can be sent via this channel simultaneously to M remote and separated locations with equal minimum excess noise in each output mode. For a set of coherent-state inputs, the channel realizes optimum symmetric 1-to-M cloning at a distance (``telecloning''). It also provides the optimal cloning of coherent states without the need of amplifying the state of interest. The generation of the multiuser quantum channel requires no more than two 10\log_{10}[(\sqrt{M}-1)/(\sqrt{M}+1)] dB squeezed states and M beam splitters.

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P. van Loock, Samuel L. Braunstein. 2000-12-13. Telecloning and multiuser quantum channels for continuous variables. https://arxiv.org/abs/quant-ph/0012063

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