Experimental implementation of a quantum game

Experimental realization of the game is presented using polarization-time-entangled photon pairs on which arbitrary (quantum-) strategies can be performed with adjustable birefringent elements. For the demonstration of the efficiency of quantum strategies, the strategy of each of the two players can be realized as a unitary transformation performed on one spin-1/2 particle. The polarization-entangled photon pairs are generated with high temporal definition in a parametric down-conversion process. Initially they are prepared in a Kraus state on which the two players perform their single-particle operations using the corresponding angular settings of a combination of λ/2- and λ/4-waveplates.