The Degree of Quantum Contextuality in terms of Concurrence for the KCBS Scenario

Abstract

Quantum contextuality is the key concept which explains the fact that the result of a measurement is not independent of the context in which it is found. It is observed to be an intrinsic feature, i.e., neither entanglement nor spatial separation is required. In this work, we revisit the previous studies which state that entanglement is an intrinsic property called self-entanglement. Using this fact, we explicitly show the correlation between quantum contextuality and concurrence in the KCBS scenario, which is the simplest approach to observing contextuality. We also derive the equation for the maximal violation of the KCBS scenario for a given concurrence and find the linear relation between them. Using this relation, we also show how the maximal violations of the KCBS and CHSH inequalities are related for an arbitrary entanglement. Moreover, we discuss the special cases of maximal entanglement, and non-entanglement for which we have found a lower local bound.