Structural approach to unambiguous discrimination of two mixed quantum states
نویسنده
چکیده
We analyze the optimal unambiguous discrimination of two arbitrary mixed quantum states. We show that the optimal measurement is unique and we present this optimal measurement for the case where the rank of the density operator of one of the states is at most 2 (“solution in 4 dimensions”). The solution is illustrated by some examples. The optimality conditions proved by Eldar et al. [Phys. Rev. A 69, 062318 (2004)] are simplified to an operational form. As an application we present optimality conditions for the measurement, when only one of the two states is detected. The current status of optimal unambiguous state discrimination is summarized via a general strategy.
منابع مشابه
Unambiguous discrimination of mixed quantum states
Quantum state discrimination is an essential problem in quantum information theory. It was first considered for pure states in the literature. One strategy of quantum state discrimination is that one is asked to distinguish the given states without error, but a non-zero probability of inconclusive answer is allowed. Such a strategy is called unambiguous discrimination. Unambiguous discriminatio...
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