Tsallis entropy for assessing quantum correlation with Bell-type inequalities in EPR experiment

• A new Bell-type inequality for nonlocal correlation in quantum systems is derived.
• The Tsallis entropy is used as a generalized metric of statistical dependence.
• It is applied to classical outcomes of quantum measurements, as in the EPR setting.
• Superiority and complementarity of the generalized Bell inequality is demonstrated.
• It is able to detect nonlocal quantum correlation from a larger set of observables.

A new Bell-type inequality is derived through the use of the Tsallis entropy to quantify the dependence between the classical outcomes of measurements performed on a bipartite quantum system, as typical of an EPR experiment. This new inequality is confronted with standard correlation-based Bell inequalities, and with other known Bell-type inequalities based on the Shannon entropy for which it constitutes a generalization. For an optimal range of the Tsallis order, the new inequality is able to detect nonlocal quantum correlation with measurements from a larger set of quantum observables. In this respect it is more powerful and also complementary compared to the previously known Bell-type inequalities.