We study the Braunstein-Kimble setup for teleportation of a quantum state of a single mode of an optical field. We assume that the sender and receiver share a two-mode Gaussian state and we identify optimum local Gaussian operations that maximize the teleportation fidelity. We consider the fidelity of teleportation of pure Gaussian states and we also introduce the fidelity of the teleportation transformation. We show in an explicit example that in some cases the optimum local operation is not a simple unitary symplectic transformation but some more general completely positive map.

• Received 1 March 2002

DOI:https://doi.org/10.1103/PhysRevA.66.012304