High-fidelity teleportation of entanglements of running-wave field states

X iv :q ua nt -p h/ 02 04 05 7v 1 1 1 A pr 2 00 2 High-fidelity teleportation of entanglements of running-wave field states R. M. Serra, C. J. Villas-Boas, N. G. de Almeida, and M. H. Y. Moussa. 1Departamento de F́ısica, Universidade Federal de São Carlos, P.O. Box 676, São Carlos, 13565-905, São Paulo, Brazil. 2Departamento de Matemática e F́ısica, Universidade Católica de Goiás, P.O. Box 86, Goiânia,74605-010, Goiás, Brazil. We describe a scheme for the teleportation of entanglements of zeroand one-photon running-wave field states. In addition to linear optical elements, Kerr nonlinearity is also employed so as to achieve a 100% probability of success in the ideal case. A comprehensive phenomenological treatment of errors in the domain of running-wave physics, for linear and nonlinear optical elements, is also given, making it possible to calculate the fidelity of the teleportation process. A strategy for carrying out the Bell-type measurement which is able to probe the absorption of photons in the optical elements is adopted. Such strategy, combined with usually small damping constants characterizing the optical devices, results in a high fidelity for the teleportation process. The feasibility of the proposed scheme relies on the fact that the Kerr nonlinearity it demands can be achieved through the recently reported ultraslow light propagation in cold atomic media [Phys. Rev. Lett. 84, 1419 (2000)].