We propose two probabilistic entanglement concentration schemes for a single copy of a two-mode squeezed vacuum state. The first scheme is based on the off-resonant interaction of a Rydberg atom with the cavity field while the second setup involves the cross Kerr interaction, an auxiliary mode prepared in a strong coherent state, and homodyne detection. We show that the continuous-variable entanglement concentration allows us to improve the fidelity of teleportation of coherent states.

• Received 31 May 2002

DOI:https://doi.org/10.1103/PhysRevA.67.022304