



01338nas a2200157   4500008004100000245004300041210004200084260001500126300001200141490000700153520091300160100002301073700002201096700001801118856004401136       2006                        eng d00aTwo-way quantum communication channels0 aTwoway quantum communication channels  c2006/02/01  a63 - 830 v043 a  We consider communication between two parties using a bipartite quantum
operation, which constitutes the most general quantum mechanical model of
two-party communication. We primarily focus on the simultaneous forward and
backward communication of classical messages. For the case in which the two
parties share unlimited prior entanglement, we give inner and outer bounds on
the achievable rate region that generalize classical results due to Shannon. In
particular, using a protocol of Bennett, Harrow, Leung, and Smolin, we give a
one-shot expression in terms of the Holevo information for the
entanglement-assisted one-way capacity of a two-way quantum channel. As
applications, we rederive two known additivity results for one-way channel
capacities: the entanglement-assisted capacity of a general one-way channel,
and the unassisted capacity of an entanglement-breaking one-way channel.
1 aChilds, Andrew, M.1 aLeung, Debbie, W.1 aLo, Hoi-Kwong  uhttp://arxiv.org/abs/quant-ph/0506039v1