



01195nas a2200157   4500008004100000245009000041210006900131260001500200300001600215490000700231520070200238100002100940700001800961700002100979856003701000       2011                        eng d00aSuperactivation of the Asymptotic Zero-Error Classical Capacity of a  Quantum Channel0 aSuperactivation of the Asymptotic ZeroError Classical Capacity o  c2011/12/01  a8114 - 81260 v573 a  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.
1 aCubitt, Toby, S.1 aChen, Jianxin1 aHarrow, Aram, W.  uhttp://arxiv.org/abs/0906.2547v3