Sequential Quantum Cloning
Quantum Physics
2015-06-26 v2
Abstract
Not all unitary operations upon a set of qubits can be implemented by sequential interactions between each qubit and an ancillary system. We analyze the specific case of sequential quantum cloning 1->M and prove that the minimal dimension D of the ancilla grows linearly with the number of clones M. In particular, we obtain D = 2M for symmetric universal quantum cloning and D = M+1 for symmetric phase-covariant cloning. Furthermore, we provide a recipe for the required ancilla-qubit interactions in each step of the sequential procedure for both cases.
Keywords
Cite
@article{arxiv.quant-ph/0607105,
title = {Sequential Quantum Cloning},
author = {Y. Delgado and L. Lamata and J. Leon and D. Salgado and E. Solano},
journal= {arXiv preprint arXiv:quant-ph/0607105},
year = {2015}
}
Comments
4 pages, no figures. New version with changes. Accepted in Physical Review Letters