Dynamics beyond completely positive maps: Some properties and applications

Hilary A. Carteret, Daniel R. Terno, Karol Zyczkowski

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73 Citations (Scopus)
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Maps that are not completely positive (CP) are often useful to describe the dynamics of open systems. An apparent violation of complete positivity can occur because there are prior correlations of the principal system with the environment, or if the applied transformation is correlated with the state of the system. We provide a physically motivated definition of accessible non-CP maps and derive two necessary conditions for a map to be accessible. We also show that entanglement between the system and the environment is not necessary to generate a non-CP dynamics. We describe two simple approximations that may be sufficient for some problems in process tomography, and then outline what these methods may be able to tell us in other situations where non-CP dynamics naturally arise.

Original languageEnglish
Article number042113
Pages (from-to)1-8
Number of pages8
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Issue number4
Publication statusPublished - 18 Apr 2008

Bibliographical note

Hilary A. Carteret, Daniel R. Terno, and Karol Zyczkowski, Physical review A, Vol. 77, Iss. 4, 042113 (2008). Copyright 2008 by the American Physical Society. The original article can be found at http://link.aps.org/doi/10.1103/PhysRevA.77.042113

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