Notes on super-operator norms induced by Schatten norms
Abstract
This paper considers basic properties of super-operator norms induced by Schatten p-norms. Such super-operator norms arise in various contexts in the study of quantum information. It is proved that for completely positive super-operators, the value of any such norm is achieved by a positive semidefinite input, answering a question recently posed by King and Ruskai. However, for any choice of p, there exists a super-operator that is the difference of two completely positive, trace-preserving super-operators such that the value of the super-operator norm is not even achieved on a Hermitian input operator. Also considered are the properties of the above norms for super-operators tensored with the identity super-operator.
Cite
@article{arxiv.quant-ph/0411077,
title = {Notes on super-operator norms induced by Schatten norms},
author = {John Watrous},
journal= {arXiv preprint arXiv:quant-ph/0411077},
year = {2007}
}
Comments
11 pages, accepted for publication in Quantum Information and Computation