Koashi-Winter relation for {\alpha}-Renyi entropies

Abstract

This work presents a generalization of the Koashi-Winter relation for $\alpha$-Renyi entropies. This result is based on the Renyi\apos s entropy version of quantum Jensen Shannon divergence. By means of this definition, a classical correlations quantifier $C_{\alpha}(\rho_{AB}) = \sup_{\xi_{AB}^{M_B}} Q_{\alpha}(\xi_{AB}^{M_B})$ is proposed, where the optimization is taken over the ensembles $\xi_{AB}^{M_B}$ created by the outputs of the local measurement process. The main result is applied to the capacity of a quantum classical channel over a tripartite pure state $\psi_{ABE}$, that is rated above in function of the probability of success to discriminate the states in the ensemble $\xi_{AE}^{M_E}$, created by the local dephasing over partition $E$, and the asymptotic log generalized robustness of partition $AB$. Some analytical results are calculated for classical correlations and entanglement of formation.