title: Equivalence between entanglement and the optimal fidelity of continuous variable teleportation.
abstract: We devise the optimal form of Gaussian resource states enabling continuous-variable teleportation with maximal fidelity. We show that a nonclassical optimal fidelity of N-user teleportation networks is necessary and sufficient for N-party entangled Gaussian resources, yielding an estimator of multipartite entanglement. The entanglement of teleportation is equivalent to the entanglement of formation in a two-user protocol, and to the localizable entanglement in a multiuser one. Finally, we show that the continuous-variable tangle, quantifying entanglement sharing in three-mode Gaussian states, is defined operationally in terms of the optimal fidelity of a tripartite teleportation network.
authors.affiliation: Dipartimento di Fisica E. R. Caianiello, Università di Salerno, CNR-Coherentia, Gruppo di Salerno, INFN Sezione di Napoli, Gruppo Collegato di Salerno, Via S. Allende, 84081 Baronissi (SA), Italy.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Adesso
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Illuminati