Addendum to "Sufficient conditions for three-particle entanglement and their tests in recent experiments"
Abstract
A recent paper [M. Seevinck and J. Uffink, Phys. Rev. A 65, 012107 (2002)] presented a bound for the three-qubit Mermin inequality such that the violation of this bound indicates genuine three-qubit entanglement. We show that this bound can be improved for a specific choice of observables. In particular, if spin observables corresponding to orthogonal directions are measured at the qubits (e.g., X and Y spin coordinates) then the bound is the same as the bound for states with a local hidden variable model. As a consequence, it can straightforwardly be shown that in the experiment described by J.-W. Pan et al. [Nature 403, 515 (2000)] genuine three-qubit entanglement was detected.
Cite
@article{arxiv.quant-ph/0505100,
title = {Addendum to "Sufficient conditions for three-particle entanglement and their tests in recent experiments"},
author = {Geza Toth and Otfried Guehne and Michael Seevinck and Jos Uffink},
journal= {arXiv preprint arXiv:quant-ph/0505100},
year = {2007}
}
Comments
Two pages, no figures, revtex4; minor changes before publication