Measurement compatibility in Bell nonlocality tests

Bell inequality, nonlocality and analyticity

The Bell and the Clauser-Horne-Shimony-Holt inequalities are shown to hold for both the cases of complex and real analytic nonlocality in the setting parameters of Einstein-Podolsky-Rosen-Bohm experiments for spin 12 particles and photons, in both the deterministic and stochastic cases. Therefore, the theoretical and experimental violation of the inequalities by quantum mechanics excludes all h...

Quantum steering, entanglement and Bell nonlocality

Quantum steering, the ability of one party to perform a measurement on their side of an entangled system with different outcomes leading to different sets of states for another part of the entangled system arbitrarily far away, is a purely quantum phenomena with no classical analogue. However, it is closely related (and indeed equivalent for pure states) to entanglement and Bell nonlocality. Th...

EPR-Bell Tests with Unsharp Observables and Relativistic Quantum Measurement

In this contribution I will review the analysis of the Einstein-Podolsky-Rosen argument [19], Bell’s inequalities [5] and of associated experiments for spins in terms of positive operator valued measures (in short: povms). Specifically, I will explore the relation between the Clauser-Horne-Shimony-Holt (CHSH) [16] inequality and a fundamental classicality property of observables – their coexist...

Bell scenarios in which nonlocality and entanglement are inversely related

Optimal tests of quantum nonlocality

We present a general method for obtaining all Bell inequalities for a given experimental setup. Although the algorithm runs slowly, we apply it to two cases. First, the Greenberger-Horne-Zeilinger setup with three observers each performing one of two possible measurements. Second, the case of two observers each performing one of three possible experiments. In both cases we obtain hundreds of in...