Phase covariant quantum cloning
Quantum Physics
2009-10-31 v1
Abstract
We consider an N -> M quantum cloning transformation acting on pure two-level states lying on the equator of the Bloch sphere. An upper bound for its fidelity is presented, by establishing a connection between optimal phase covariant cloning and phase estimation. We give the explicit form of a cloning transformation that achieves the bound for the case N=1, M=2, and find a link between this case and optimal eavesdropping in the quantum cryptographic scheme BB84.
Cite
@article{arxiv.quant-ph/9909046,
title = {Phase covariant quantum cloning},
author = {D. Bruss and M. Cinchetti and G. M. D'Ariano and C. Macchiavello},
journal= {arXiv preprint arXiv:quant-ph/9909046},
year = {2009}
}
Comments
9 pages, 1 figure