English

Extending additivity from symmetric to asymmetric channels

Quantum Physics 2009-11-11 v4

Abstract

We prove a lemma which allows one to extend results about the additivity of the minimal output entropy from highly symmetric channels to a much larger class. A similar result holds for the maximal output pp-norm. Examples are given showing its use in a variety of situations. In particular, we prove the additivity and the multiplicativity for the shifted depolarising channel.

Cite

@article{arxiv.quant-ph/0505022,
  title  = {Extending additivity from symmetric to asymmetric channels},
  author = {Motohisa Fukuda},
  journal= {arXiv preprint arXiv:quant-ph/0505022},
  year   = {2009}
}

Comments

8 pages. This is the latest version of the first half of the original paper. The other half will appear in another paper

R2 v1 2026-07-22T19:48:55.797Z