Generalized measurements for optimally discriminating two mixed states and their linear-optical implementation
Ulrike Herzog, Oliver J. Benson · Journal of Modern Optics · 2009
Measurement schemes for discriminating two given mixed states of a quantum system have been optimized with respect to various criteria. In many cases the optimum measurements are generalized ones, characterized by detection operators that are not projectors. Here we focus on two generalized measurements. The first refers to the discrimination of two mixed qubit states with maximum confidence at a minimum probability of inconclusive results, and the second to the optimum unambiguous discrimination of two mixed states that are connected by a special similarity transformation. For both measurements we consider linear-optical implementations using single-photon polarization states.