Entanglement cost of discriminating noisy Bell states by local operations and classical communication

Abstract

Entangled states can help in quantum state discrimination by local operations and classical communication (LOCC). For example, a Bell state is necessary (and sufficient) to perfectly discriminate a set of either three or four Bell states by LOCC. In this paper, we consider the task of LOCC discrimination of the states of noisy Bell ensembles, where a given ensemble consists of the states obtained by mixing the Bell states with an arbitrary two-qubit state with nonzero probabilities. It is proved that a Bell state is required for optimal discrimination by LOCC, even though the ensembles do not contain, in general, any maximally entangled state, and in specific instances, any entangled state.

20 pages; v2: revised title and abstract, new references added, other minor edits; v3: minor edits to match the published version

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Cited by in corpus (7)

• Bound on local minimum-error discrimination of bipartite quantum states
• Bipartite quantum state discrimination and decomposable entanglement witness
• Bound on optimal local discrimination of multipartite quantum states
• Locally distinguishing a maximally entangled basis using shared entanglement
• Quantum Coherence and Distinguishability as Complementary Resources: A Resource-Theoretic Perspective from Wave-Particle Duality
• Attainability of quantum state discrimination bounds with collective measurements on finite copies
• Trade-off between Information Gain and Disturbance in Local Discrimination of Entangled Quantum States