English

Realistic limits on the nonlocality of an N-partite single-photon superposition

Quantum Physics 2012-01-10 v2

Abstract

A recent paper [L. Heaney, A. Cabello, M. F. Santos, and V. Vedral, New Journal of Physics, 13, 053054 (2011)] revealed that a single quantum symmetrically delocalized over N modes, namely a W state, effectively allows for all-versus-nothing proofs of nonlocality in the limit of large N. Ideally, this finding opens up the possibility of using the robustness of the W states while realizing the nonlocal behavior previously thought to be exclusive to the more complex class of Greenberger-Horne-Zeilinger (GHZ) states. We show that in practice, however, the slightest decoherence or inefficiency of the Bell measurements on W states will degrade any violation margin gained by scaling to higher N. The non-statistical demonstration of nonlocality is thus proved to be impossible in any realistic experiment.

Keywords

Cite

@article{arxiv.1110.5802,
  title  = {Realistic limits on the nonlocality of an N-partite single-photon superposition},
  author = {Amine Laghaout and Gunnar Björk and Ulrik L. Andersen},
  journal= {arXiv preprint arXiv:1110.5802},
  year   = {2012}
}

Comments

6 pages, 6 figures