Bounds on unambiguous discrimination between quantum states.

In this paper, we present a general upper bound on the success probability for unambiguous discrimination among arbitrary m mixed quantum states with given a priori probability. We further analyze how this upper bound can be achievable by presenting a sufficient condition related to it, and we compare this upper bound with three other upper bounds. Moreover, for the issue of the unambiguous identification of m unknown multicopy qudit pure states, we also get a bound [ABSTRACT FROM AUTHOR]