QUANTUM NONLOCALITY OF POLARIZATION-MOMENTUM HYPER-ENTANGLED STATES

We present two experimental tests of nonlocality, namely the Bell's inequalities and the "All Versus Nothing" (AVN) proof, performed with a two photon hyper-entangled state, entangled in polarization and momentum. These states, which double the extension of the available qubits, are engineered by a simple experimental method which uses linear optics and a single Type I nonlinear crystal. The AVN test of local realism represents a generalization of the GHZ to the case of two entangled particles and two observers.