All-Versus-Nothing Violation of Local Realism by Two-Photon,   Four-Dimensional Entanglement
  We develop and exploit a source of two-photon four-dimensional entanglement to report the first two-particle all-versus-nothing test of local realism with a linear optics setup, but without resorting to a non-contextuality ssumption. Our experimental results are in well agreement with quantum mechanics while in extreme contradiction with local realism. Potential applications of our experiment are briefly discussed. 
Tao Yang, Qiang Zhang, Jun Zhang, Juan Yin, Zhi Zhao, Marek Zukowski,   Zeng-Bing Chen, Jian-Wei Pan