M. E. Shirokov, T. V. Shulman, “On superactivation of one-shot zero-error quantum capacity and the related property of quantum measurements”, Probl. Peredachi Inf., 2014, Volume 50, Issue 3,Pages <nobr>35

This article is cited in 8 papers

Information Theory

On superactivation of one-shot zero-error quantum capacity and the related property of quantum measurements

M. E. Shirokov^a, T. V. Shulman^b

^a Steklov Mathematical Institute of Russian Academy of Sciences, Moscow, Russia
^b University of Copenhagen, Copenhagen, Denmark

Abstract: We give a detailed description of a low-dimensional quantum channel (input dimension 4, Choi rank 3) demonstrating the symmetric form of superactivation of one-shot quantum zero-error capacity. This property means appearance of a noiseless (perfectly reversible) subchannel in the tensor square of a channel having no noiseless subchannels. Then we describe a quantum channel with an arbitrary given level of symmetric superactivation (including the infinite value). We also show that superactivation of one-shot quantum zero-error capacity of a channel can be reformulated in terms of quantum measurement theory as appearance of an indistinguishable subspace for the tensor product of two observables having no indistinguishable subspaces.

UDC: 621.391.1+519.72

Received: 03.03.2014