Positive-operator-valued measure optimization of classical correlations

We study the problem of optimization over positive-operator-valued measures to extract classical correlation in a bipartite quantum system. The proposed method is applied to binary states only. Moreover, to illustrate this method, an explicit example is studied in detail.

Figure 1

We plot as a function of $p$ the classical correlation $C_B$ (lower curve) evaluated using the best orthogonal POVM, and the mutual information $I(A:B)$ (higher curve). The vertical strips are sets of large numbers of dots representing the obtained value of the classical correlation for the different randomly generated events.