title: Quantifying nonclassicality of one-mode Gaussian states of the radiation field.
abstract: We define the degree of nonclassicality of a one-mode Gaussian state of the quantum electromagnetic field in terms of the Bures distance between the state and the set of all classical one-mode Gaussian states. We find the closest classical Gaussian state and the degree of nonclassicality using a recently established expression for the Uhlmann fidelity of two single-mode Gaussian states. The decrease of nonclassicality under thermal mapping is carefully analyzed. Along the same lines, we finally present the evolution of nonclassicality during linear amplification.
authors.affiliation: Institute for Theoretical Atomic and Molecular Physics, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA.
authors.forename: Paulina
authors.initials: P
authors.lastname: Marian
authors.forename: Tudor A
authors.initials: TA
authors.lastname: Marian
authors.forename: Horia
authors.initials: H
authors.lastname: Scutaru