Maximum observable correlation for a bipartite quantum system

Hall, Michael J.W. and Andersson, Erika and Brougham, Thomas (2006) Maximum observable correlation for a bipartite quantum system. Physical Review A, 74 (6). ISSN 1050-2947 (https://doi.org/10.1103/PhysRevA.74.062308)

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Abstract

The maximum observable correlation between the two components of a bipartite quantum system is a property of the joint density operator, and is achieved by making particular measurements on the respective components. For pure states it corresponds to making measurements diagonal in a corresponding Schmidt basis. More generally, it is shown that the maximum correlation may be characterized in terms of a correlation basis for the joint density operator, which defines the corresponding (nondegenerate) optimal measurements. The maximum coincidence rate for spin measurements on two-qubit systems is determined to be (1+s)/2, where s is the spectral norm of the spin correlation matrix, and upper bounds are obtained for n-valued measurements on general bipartite systems. It is shown that the maximum coincidence rate is never greater than the computable cross norm measure of entanglement, and a much tighter upper bound is conjectured. Connections with optimal state discrimination and entanglement bounds are briefly discussed.

  • Item type:Article
    ID code:6197
    Dates:
    Date
    Event
    18 December 2006
    Published
    Subjects:Science > Physics > Optics. Light
    Department:Faculty of Science > Physics
    Depositing user: Miss Darcy Spiller
    Date deposited:02 Jun 2008
    Last modified:08 Apr 2024 16:07
    URI:https://strathprints.strath.ac.uk/id/eprint/6197
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