Superactivation of the Asymptotic Zero-Error Classical Capacity of a Quantum Channel
Abstract
The zero-error classical capacity of a quantum channel is the asymptotic rate at which it can be used to send classical bits perfectly, so that they can be decoded with zero probability of error. We show that there exist pairs of quantum channels, neither of which individually have any zero-error capacity whatsoever (even if arbitrarily many uses of the channels are available), but such that access to even a single copy of both channels allows classical information to be sent perfectly reliably. In other words, we prove that the zero-error classical capacity can be superactivated. This result is the first example of superactivation of a classical capacity of a quantum channel.
Keywords
Cite
@article{arxiv.0906.2547,
title = {Superactivation of the Asymptotic Zero-Error Classical Capacity of a Quantum Channel},
author = {Toby S. Cubitt and Jianxin Chen and Aram W. Harrow},
journal= {arXiv preprint arXiv:0906.2547},
year = {2012}
}
Comments
24 pages. Despite the similar title, contains different results from arXiv:0906.2527. See "Note Added" at end of paper for details. V2: Includes significantly revised proof of Theorem 27. V3: Includes expanded explanation of some of the technical details