Optimal estimation of two-qubit pure-state entanglement

We present optimal measuring strategies for an estimation of the entanglement of unknown two-qubit pure states and of the degree of mixing of unknown single-qubit mixed states, of which N identical copies are available. The most general measuring strategies are considered in both situations, to conc...

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Detalles Bibliográficos
Autores: Acín dal Maschio, Antonio, Tarrach, R., 1948-, Vidal Bonafont, Guifré
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2000
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/9563
Acceso en línea:https://hdl.handle.net/2445/9563
Access Level:acceso abierto
Palabra clave:Teoria de la informació
Teoria quàntica
Information theory
Quantum theory
Descripción
Sumario:We present optimal measuring strategies for an estimation of the entanglement of unknown two-qubit pure states and of the degree of mixing of unknown single-qubit mixed states, of which N identical copies are available. The most general measuring strategies are considered in both situations, to conclude in the first case that a local, although collective, measurement suffices to estimate entanglement, a nonlocal property, optimally.