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arXiv · 0804.3100

Geometry of depolarizing channels

Kuldeep Dixit·E. C. G. Sudarshan
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Abstract

Depolarizing maps acting on an N dimensional system are completely positive maps resulting into compression of the Bloch ball along the different polarization directions. In the qubit case these maps are a convex sum of four extremal maps and form a simplex in the space of compression coefficients along the three polarization directions. We calculate the compression domain for three and four level systems. For a three level system the region has curved surfaces, but it is a simplex for a four level system. We conjecture that it is a simplex in the case of 2^n level systems.

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Kuldeep Dixit, E. C. G. Sudarshan. 2008-04-18. Geometry of depolarizing channels. https://doi.org/10.1103/physreva.78.032308

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