English

Entanglement cost of implementing controlled-unitary operations

Quantum Physics 2011-10-28 v2

Abstract

We investigate the minimum entanglement cost of the deterministic implementation of two-qubit controlled-unitary operations using local operations and classical communication (LOCC). We show that any such operation can be implemented by a three-turn LOCC protocol, which requires at least 1 ebit of entanglement when the resource is given by a bipartite entangled state with Schmidt number 2. Our result implies that there is a gap between the minimum entanglement cost and the entangling power of controlled-unitary operations. This gap arises due to the requirement of implementing the operations while oblivious to the identity of the inputs.

Keywords

Cite

@article{arxiv.1008.1128,
  title  = {Entanglement cost of implementing controlled-unitary operations},
  author = {Akihito Soeda and Peter S. Turner and Mio Murao},
  journal= {arXiv preprint arXiv:1008.1128},
  year   = {2011}
}

Comments

5 pages + 13 pages of appendix, comments welcome (published version)

R2 v1 2026-06-21T15:57:46.050Z