Optical Test on Greenberger-Horne-Zeilinger Paradox of Quantum Nonlocality

Abstract

Recently we proposed a truly generalized Greenberger-Horne-Zeilinger (GHZ) paradox in a tripartite system with each subsystem of arbitrary dimension. A GHZ paradox directly implies the presence of GHZ entanglement in the tripartite system. It plays a crucial role in quantum information processing. We present an optically realizable experiment by using interferometers to test a generalized GHZ paradox of arbitrary even dimension. The scheme requires parametric down converters, single-photon detectors, and simple linear optical devices such as polarized/unpolarized beam splitters, and phase shifters.