Classical extension of quantum-correlated separable states

Li and Luo [Phys. Rev. A 78 (2008) 024303] discovered a remarkable relation between discord and entanglement. It establishes that all separable states can be obtained via reduction of a classically-correlated state "living" in a space of larger dimension. Starting from this result, we disc...

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Detalhes bibliográficos
Autores: Bellomo, Guido, Plastino, Ángel Luis, Plastino, Ángel Ricardo
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/50026
Acesso em linha:http://hdl.handle.net/11336/50026
Access Level:acceso abierto
Palavra-chave:Entanglement And Separability
Quantum Correlations
Quantum Discord
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descrição
Resumo:Li and Luo [Phys. Rev. A 78 (2008) 024303] discovered a remarkable relation between discord and entanglement. It establishes that all separable states can be obtained via reduction of a classically-correlated state "living" in a space of larger dimension. Starting from this result, we discuss here an optimal classical extension of separable states and explore this notion for low-dimensional systems. We find that the larger the dimension of the classical extension, the larger the discord in the original separable state. Further, we analyze separable states of maximum discord in ℂ2 ⊗ ℂ2 and their associated classical extensions showing that, from the reduction of a classical state in ℂ2 one can obtain a separable state of maximum discord in 2 2.