Show simple item record 2016-09-13T11:22:30Z 2016-09-13T11:22:30Z
dc.title Generalized conditional entropy optimization for qudit-qubit states en
dc.type Artículo es
dcterms.abstract We derive a general approximate solution to the problem of minimizing the conditional entropy of a quditqubit system resulting from a local measurement on the qubit, which is valid for general entropic forms and becomes exact in the limit of weak correlations. This entropy measures the average conditional mixedness of the postmeasurement state of the qudit, and its minimum among all local measurements represents a generalized entanglement of formation. In the case of the von Neumann entropy, it is directly related to the quantum discord. It is shown that at the lowest nontrivial order, the problem reduces to the minimization of a quadratic form determined by the correlation tensor of the system, the Bloch vector of the qubit and the local concavity of the entropy, requiring just the diagonalization of a 3 × 3 matrix. A simple geometrical picture in terms of an associated correlation ellipsoid is also derived, which illustrates the link between entropy optimization and correlation access and which is exact for a quadratic entropy. The approach enables a simple estimation of the quantum discord. Illustrative results for two-qubit states are discussed. en
dcterms.extent 11 p. es
dcterms.issued 2014
dcterms.language Inglés es
dcterms.license Attribution 4.0 International (BY 4.0) es
dcterms.publisher APS physics es
dcterms.subject quantum communication en
dcterms.subject entanglement measures en
dcterms.subject quantum mechanics en
dcterms.subject measurement theory en
cic.version info:eu-repo/semantics/submittedVersion es Gigena, Nicolás es Rossignoli, Raúl Dante es
cic.lugarDesarrollo Universidad Nacional de La Plata es
dcterms.subject.materia Ciencias Físicas es
dcterms.identifier.url Documento completo es
dcterms.identifier.other DOI: 10.1103/PhysRevA.90.042318 es
dcterms.isPartOf.issue vol. 90, nº 4 es
dcterms.isPartOf.series Physical Review A es
cic.isPeerReviewed true es
cic.isFulltext true es


  • Icon

    Documento completo 

    PDF file (1015.Kb)

  • This item appears in the following Collection(s)

    Show simple item record