2000/09/26 by Massimiliano F. Sacchi · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physreva.63.054104
published as Phys. Rev. A 63, 054104 (2001) · 4 pages, 2 figures, 1 table
arxiv created 2000/09/26 · arxiv updated 2009/12/01
We present a method for the determination of the completely positive (CP) map describing a physical device based on random preparation of the input states, random measurements at the output, and maximum-likelihood principle. In the numerical implementation the constraint of completely positivity can be imposed by exploiting the isomorphism between linear transformations from Hilbert spaces \cal H to \cal K and linear operators in \cal K⊗ \cal H. The effectiveness of the method is shown on the basis of some examples of reconstruction of CP maps related to quantum communication channels for qubits.