On Weyl-covariant channels

Abstract

Formalism of discrete noncommutative Fourier transform is developed and applied to the study of Weyl-covariant channels. We then extend a result in quant-ph/0509126 concerning a bound of the maximal output 2-norm of a Weyl-covariant channel. A class of channels which attain the bound is introduced, for which the multiplicativity of the maximal output 2-norm is proven. Complementary channels are described which share the multiplicativity properties with the Weyl-covariant channels.

14 pages, 1 figure, some errors were corrected

References in corpus (2)

• Properties of Conjugate Channels with Applications to Additivity and Multiplicativity
• On complementary channels and the additivity problem

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