title: Quantum Correlations Are Stronger Than All Nonsignaling Correlations Produced by n-Outcome Measurements.
abstract: We show that, for any n, there are m-outcome quantum correlations, with m>n, which are stronger than any nonsignaling correlation produced from selecting among n-outcome measurements. As a consequence, for any n, there are m-outcome quantum measurements that cannot be constructed by selecting locally from the set of n-outcome measurements. This is a property of the set of measurements in quantum theory that is not mandatory for general probabilistic theories. We also show that this prediction can be tested through high-precision Bell-type experiments and identify past experiments providing evidence that some of these strong correlations exist in nature. Finally, we provide a modified version of quantum theory restricted to having at most n-outcome quantum measurements.
authors: Department of Theoretical Physics, University of the Basque Country UPV/EHU, P.O. Box 644, E-48080 Bilbao, Spain.
authors: Matthias
authors: M
authors: Kleinmann
authors: Departamento de Física Aplicada II, Universidad de Sevilla, E-41012 Sevilla, Spain.
authors: Adán
authors: A
authors: Cabello