Various quantum nonlocality tests with a commercial two-photon entanglement source

Authors:Enrico Pomarico, Jean-Daniel Bancal, Bruno Sanguinetti, Anas Rochdi, Nicolas Gisin
Journal:Phys. Rev. A 83, 052104 (2011)
DOI:http://dx.doi.org/10.1103/PhysRevA.83.052104
Abstract:Nonlocality is a fascinating and counterintuitive aspect of nature, revealed by the violation of a Bell inequality. The standard and easiest configuration in which Bell inequalities can be measured has been proposed by Clauser-Horne-Shimony-Holt (CHSH). However, alternative nonlocality tests can also be carried out. In particular, Bell inequalities requiring multiple measurement settings can provide deeper fundamental insights about quantum nonlocality, as well as offering advantages in the presence of noise and detection inefficiency. In this paper we show how these nonlocality tests can be performed using a commercially available source of entangled photon pairs. We report the violation of a series of these nonlocality tests (I3322, I4422, and chained inequalities). With the violation of the chained inequality with 4 settings per side we put an upper limit at 0.49 on the local content of the states prepared by the source (instead of 0.63 attainable with CHSH). We also quantify the amount of true randomness that has been created during our experiment (assuming fair sampling of the detected events).
File:physreva.83.052104.pdf

BibTeX Source

@Article{PhysRevA.83.052104,
  title =        "Various quantum nonlocality tests with a commercial two-photon entanglement
                 source",
  author =       "Enrico Pomarico and Jean-Daniel Bancal and Bruno Sanguinetti and Anas Rochdi and
                 Nicolas Gisin",
  journal =      "Phys. Rev. A",
  volume =       "83",
  number =       "5",
  pages =        "052104",
  numpages =     "7",
  year =         "2011",
  month =        may,
  doi =          "10.1103/PhysRevA.83.052104",
  publisher =    "American Physical Society",
  abstract =     "Nonlocality is a fascinating and counterintuitive aspect of nature, revealed by
                 the violation of a Bell inequality. The standard and easiest configuration in which
                 Bell inequalities can be measured has been proposed by Clauser-Horne-Shimony-Holt
                 (CHSH). However, alternative nonlocality tests can also be carried out. In
                 particular, Bell inequalities requiring multiple measurement settings can provide
                 deeper fundamental insights about quantum nonlocality, as well as offering
                 advantages in the presence of noise and detection inefficiency. In this paper we
                 show how these nonlocality tests can be performed using a commercially available
                 source of entangled photon pairs. We report the violation of a series of these
                 nonlocality tests (I3322, I4422, and chained inequalities). With the violation of
                 the chained inequality with 4 settings per side we put an upper limit at 0.49 on
                 the local content of the states prepared by the source (instead of 0.63 attainable
                 with CHSH). We also quantify the amount of true randomness that has been created
                 during our experiment (assuming fair sampling of the detected events).",
}