title: Experimental violation of local realism by four-photon Greenberger-Horne-Zeilinger entanglement.
abstract: We report the first experimental violation of local realism by four-photon Greenberger-Horne-Zeilinger (GHZ) entanglement. In the experiment, the nonstatistical GHZ conflicts between quantum mechanics and local realism are confirmed, within the experimental accuracy, by four specific measurements of polarization correlations between four photons. In addition, our experimental results also demonstrate a strong violation of Mermin-Ardehali-Belinskii-Klyshko inequality by 76 standard deviations. Such a violation can only be attributed to genuine four-photon entanglement.
authors: Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China.
authors: Zhi
authors: Z
authors: Zhao
authors: Tao
authors: T
authors: Yang
authors: Yu-Ao
authors: YA
authors: Chen
authors: An-Ning
authors: AN
authors: Zhang
authors: Marek
authors: M
authors: Zukowski
authors: Jian-Wei
authors: JW
authors: Pan