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arXiv · 2106.08721

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

Somshubhro Bandyopadhyay·Vincent Russo
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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.

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Somshubhro Bandyopadhyay, Vincent Russo. 2021-06-16. Entanglement cost of discriminating noisy Bell states by local operations and classical communication. https://doi.org/10.1103/physreva.104.032429

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