Continuous variable quantum teleportation with sculptured and noisy non-Gaussian resources
Dipartimento di Matematica e Informatica, Università degli Studi di Salerno, via Ponte don Melillo, 84084 Fisciano (SA), Italy
2 CNR-INFM Coherentia, Napoli, Italy, and INFN Sezione di Napoli, Gruppo collegato di Salerno, Baronissi (SA), Italy
3 Dipartimento di Fisica, Università degli Studi di Salerno, via S. Allende, 84081 Baronissi (SA), Italy
4 ISI Foundation for Scientific Interchange, Viale Settimio Severo 65, 00173 Torino, Italy
We investigate continuous variable (CV) quantum teleportation using relevant classes of non-Gaussian states of the radiation field as entangled resources. First, we introduce the class two-mode squeezed symmetric superposition of Fock states, including finite truncations of twin-beam Gaussian states as special realizations. These states depend on a set of free independent parameters that can be adjusted for the optimization of teleportation protocols, with an enhancement of the success probability of teleportation both for coherent and Fock input states. We show that the optimization procedure reduces the entangled resources to truncated twin beam states, which thus represents an optimal class of non-Gaussian resources for quantum teleportation. We then introduce a further class of two-mode non-Gaussian entangled resources, in the form of squeezed cat-like states. We analyze the performance and the properties of such states when optimized for (CV) teleportation, and compare them to the optimized squeezed Bell-like states introduced in a previous work . We discuss how optimal resources for teleportation are characterized by a suitable balance of entanglement content and squeezed vacuum affinity. We finally investigate the effects of thermal noise on the efficiency of quantum teleportation. To this aim, a convenient framework is to describe noisy entangled resources as linear superpositions of non-Gaussian state and thermal states. Although the presence of the thermal component strongly reduces the teleportation fidelity, noisy non-Gaussian states remain preferred resources when compared to noisy twin-beam Gaussian states.
© EDP Sciences, Springer-Verlag, 2008