Parametric separation of symmetric pure quantum states

Abstract

Quantum state separation is a probabilistic map that transforms a given set of pure states into another set of more distinguishable ones. Here we investigate such a map acting onto uniparametric families of symmetric linearly dependent or independent quantum states. We obtained analytical solutions for the success probability of the maps--which is shown to be optimal--as well as explicit constructions in terms of positive operator valued measures. Our results can be used for state discrimination strategies interpolating continuously between minimum-error and unambiguous (or maximum-confidence) discrimination, which, in turn, have many applications in quantum information protocols. As an example, we show that quantum teleportation through a nonmaximally entangled quantum channel can be accomplished with higher probability than the one provided by unambiguous (or maximum-confidence) discrimination and with higher fidelity than the one achievable by minimum-error discrimination. Finally, an optical network is proposed for implementing parametric state separation.

13 pages, 5 figures

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Cited by in corpus (4)

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• Optimal probabilistic dense coding schemes
• Coherence based on positive operator-valued measures for standard and concatenated quantum state discrimination with inconclusive results
• Experimental optimal discrimination of $N$ states of a qubit with fixed rates of inconclusive outcomes