  We study the activation of entanglement in teleportation protocols. To this
end, we a present derivation of the average fidelity of teleportation process
with noisy classical channel for qudits. In our work we do not make any
assumptions about the entangled states shared by communicating parties. Our
result allows us to specify the minimum amount of classical information
required to beat the classical limit when the protocol is based on the Bell
measurements. We also compare average fidelity of teleportation obtained using
noisy and perfect classical channel with restricted capacity. The most
important insight into the intricacies of quantum information theory that we
gain is that though entanglement, obviously, is a necessary resource for
efficient teleportation it requires a certain threshold amount of classical
communication to be more useful than classical communication. Another
interesting finding is that the amount of classical communication required to
activate entanglement for teleportation purposes depends on the dimension d of
the system being teleported but is not monotonic reaching maximum for d = 4.

Quantum Physics