Unambiguous discrimination between two rank-2 mixed quantum states
Mihailo Stojnic, Babak Hassibi · 2007
In this paper we consider the problem of the optimal quantum unambiguous detection between two mixed quantum states. More specifically, we consider two mixed quantum states of rank 2 which lie in a Hilbert space of dimension 4. Using duality theory we explicitly characterize the optimal measurement operators. Furthermore, as a by-product of our framework we obtain a closed form solution of unambiguous discrimination between a pure and a mixed quantum state.