Entanglement, mixedness and perfect local discrimination of orthogonal quantum states

Abstract

It is shown that local distinguishability of orthogonal mixed states can be completely characterized by local distinguishability of their supports irrespective of entanglement and mixedness of the states. This leads to two kinds of upper bounds on the number of perfect LOCC distinguishable orthogonal mixed states. The first one depends only on pure-state entanglement within the supports of the states, and therefore may be easy to compute in many instances. The second bound is optimal in the sense that it optimizes the bounding quantities, not necessarily function of entanglement alone, over all orthogonal mixed state ensembles (satisfying certain conditions) admissible within the supports of the density matrices.

Latex, 12 pages; journal version

References in corpus (7)

• Quantum entanglement
• Distinguishing Arbitrary Multipartite Basis Unambiguously Using Local Operations and Classical Communication
• Entanglement of multiparty stabilizer, symmetric, and antisymmetric states
• Distinguishability of Quantum States by Separable Operations
• More nonlocality with less purity
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Cited by in corpus (14)

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• Strong quantum nonlocality with entanglement
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• Strong quantum nonlocality in $N$-partite systems
• Strong quantum nonlocality for unextendible product bases in heterogeneous systems
• Entanglement assisted state discrimination and entanglement preservation
• Strong quantum nonlocality and unextendibility without entanglement in $N$-partite systems with odd $N$
• Separability and entanglement in superpositions of quantum states
• An entropic analysis of approximate quantum error correction
• Strong quantum nonlocality from hypercubes
• Incompatibility of local measurements provide advantage in local quantum state discrimination
• Locally unidentifiable subset of quantum states and its resourcefulness in secret password distribution
• Quantum nonlocality without entanglement depending on nonzero prior probabilities in optimal unambiguous discrimination
• Global versus Local Discrimination of Locally Implementable Multipartite Unitaries