Continuous variable teleportation as a quantum channel

A quantum channel consisting of continuous variable quantum teleportation based on the standard protocol is investigated. It is shown that a quantum channel for continuous variable teleportation by an aribitrary entangled state is equivalent to a generalized thermalizing channel. We also study the transmission of nonclassical states by a teleportation channel with a two-mode squeezed-vacuum state in a noisy environment. The transmisson performance is evaluated by using the Glauber-Sudarshan P function and the nonclassical depth. Finally, we compare the results obtained to those of a noisy direct transmission channel. It is shown that the teleportation channel performs better than the direct transmission channel in a certain region. (C) 2003 MAIK "Nauka/Interperiodica".