LADDER PROOF OF NONLOCALITY WITHOUT INEQUALITIES - THEORETICAL AND EXPERIMENTAL RESULTS

We show how a previous demonstration of nonlocality without inequaliti es for two spin-half particles can be improved so that a greater propo rtion of the pairs are shown to be subject to a contradiction with loc al realism. This is achieved by considering more settings of the appar atus at each end. Also, we report on an experimental realization emplo ying a tunable source of polarization entangled photons. The experimen tal results violate locality (module, the efficiency loophole).