English

A quantum channel with additive minimum output entropy

Quantum Physics 2007-05-23 v1

Abstract

We give a direct proof of the additivity of the minimum output entropy of a particular quantum channel which breaks the multiplicativity conjecture. This yields additivity of the classical capacity of this channel, a result obtained by a different method by Matsumoto and Yura [quant-ph/0306009]. Our proof relies heavily upon certain concavity properties of the output entropy which are of independent interest.

Keywords

Cite

@article{arxiv.quant-ph/0403072,
  title  = {A quantum channel with additive minimum output entropy},
  author = {Nilanjana Datta and Alexander S. Holevo and Yuri M. Suhov},
  journal= {arXiv preprint arXiv:quant-ph/0403072},
  year   = {2007}
}

Comments

15 pages, 2 figures