title: Experimental estimation of entanglement at the quantum limit.
abstract: Entanglement is the central resource of quantum information processing and the precise characterization of entangled states is a crucial issue for the development of quantum technologies. This leads to the necessity of a precise, experimental feasible measure of entanglement. Nevertheless, such measurements are limited both from experimental uncertainties and intrinsic quantum bounds. Here we present an experiment where the amount of entanglement of a family of two-qubit mixed photon states is estimated with the ultimate precision allowed by quantum mechanics.
authors.affiliation: INRIM, I-10135, Torino, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Brida
authors.forename: Ivo Pietro
authors.initials: IP
authors.lastname: Degiovanni
authors.forename: Angela
authors.initials: A
authors.lastname: Florio
authors.forename: Marco
authors.initials: M
authors.lastname: Genovese
authors.forename: Paolo
authors.initials: P
authors.lastname: Giorda
authors.forename: Alice
authors.initials: A
authors.lastname: Meda
authors.forename: Matteo G A
authors.initials: MG
authors.lastname: Paris
authors.forename: Alexander
authors.initials: A
authors.lastname: Shurupov