Test of nonlocality for a continuos-variable state based on arbitrary   number of measurement outcomes
  We propose a scheme to test Bell's inequalities for an arbitrary number of measurement outcomes on entangled continuous variable states. The Bell correlation functions are expressible in terms of phase-space quasiprobability functions with complex ordering parameter, which can experimentally be determined both directly via local CV-qubit interaction or indirectly via tomographic reconstructions. We demonstrate that continuous-variable systems can give stronger violations of these Bell's inequalities than of the ones developed for two-outcome observables. Thus, while keeping the feasibility of the phase-space approach, our scheme increases its efficiency. 
W. Son, C. Brukner, M. S. Kim