Gaussian quantum channels have recently attracted a growing interest, since
they may lead to a tractable approach to the generally hard problem of
evaluating quantum channel capacities. However, the analysis performed so far
has always been restricted to memoryless channels. Here, we consider the case
of a bosonic Gaussian channel with memory, and show that the classical capacity
can be significantly enhanced by employing entangled input symbols instead of
product symbols.Comment: 13 pages, 5 figures, Workshop on Quantum entanglement in physical and
information sciences, Pisa, December 14-18, 200