  We study the transmission of both classical or quantum information through
all the phases of a finite XXZ spin chain. This characterizes the merit of the
different phases in terms of their ability to act as a quantum wire. As far as
quantum information is concerned, we need only consider the transmission of
entanglement as the direct transmission of a quantum state is equivalent. The
isotropic anti-ferromagnetic spin chain is found to be the optimal point of the
phase diagram for the transmission of quantum entanglement when one considers
both the amount of transmitted entanglement, as well as the velocity with which
it is transmitted. But this optimal point in the phase diagram moves to the
Neel phase when decoherence or thermal fluctuations are taken to account. This
chain may also be able to transfer classical information even when, due to a
large magnitude of the noise, quantum information is not transmitted at all.
For a certain range of anisotropies of the model, a curious feature is found in
the flow of quantum information inside the chain, namely, a hopping mode of
entanglement transfer which skips the odd numbered sites. Our predictions will
potentially be testable in several physical systems.
