Monogamy relations of entropic non-contextual inequalities and their experimental demonstration

Abstract

We analyze monogamous relationships of abritrary entropic non-contextuality (ENC) inequalities via a graph theoretic approach. While ENC inequalities are important in quantum information theory, a theoretical and experimental understanding of their monogamous nature is still elusive. We analyze conditions for ENC inequalities to exhibit a monogamous relationship and derive the same explicitly for an entropic version of the Bell-CHSH scenario. Next, we consider two different sets of three qubit states and experimentally show that they exhibit monogamy of entropic Bell-CHSH inequality. The monogamous relationship of these inequalities is theoretically exhibited via an insightful proof and is experimentally demonstrated on an NMR quantum information processor.
We also develop a novel and easy-to-implement experimental method to evaluate entropies on an NMR quantum information processor
using only the information about expectation values of the observables.