On the upper bound of classical correlations in a bipartite quantum system

Theresa Christ, Haye Hinrichsen

Published 2017-02-23Version 1

For a bipartite quantum system consisting of subsystems A and B it was shown in J. Phys. A: Math. Theor. 45 (2012) 025301 that the amount of classical correlations, which is used to define quantum discord, is bounded from above by the minimum of the von Neumann entropies of the subsystems A and B. We provide an alternative proof that is generalized to POVMs and that is more transparent as it works without defining correlation matrices.