English

Quantum Cloning without Interference

Quantum Physics 2015-05-13 v1

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.

Keywords

Cite

@article{arxiv.0807.1657,
  title  = {Quantum Cloning without Interference},
  author = {Benoit Roubert and Daniel Braun},
  journal= {arXiv preprint arXiv:0807.1657},
  year   = {2015}
}

Comments

14 pages revtex, 1 eps figure

R2 v1 2026-06-21T10:59:17.880Z