Strong polygamy of multi-party q-expected quantum correlations

Abstract

We show that the polygamous nature of multi-party quantum correlations can be characterized in a stronger form based on Tsallis q-entropy and q-expectation value; we establish a class of strong polygamy inequalities of multi-party entanglement in terms of Tsallis q-entropy and q-expectation value for \(q \ge 1\). Our new class of inequalities is tighter than the usual polygamy inequalities of multi-party entanglement, and the tightness is explicitly illustrated by an example. Moreover, our new class of inequalities is concerned with the entanglement distributed between a single party and any possible subsets of the rest parties, whereas the usual polygamy inequality only considers the entanglement between one party and another. We further establish the equivalence between strong polygamy of quantum entanglement and quantum discord distributed in multi-party quantum systems.