title: Measures of quantum synchronization in continuous variable systems.
abstract: We introduce and characterize two different measures which quantify the level of synchronization of coupled continuous variable quantum systems. The two measures allow us to extend to the quantum domain the notions of complete and phase synchronization. The Heisenberg principle sets a universal bound to complete synchronization. The measure of phase synchronization is, in principle, unbounded; however, in the absence of quantum resources (e.g., squeezing) the synchronization level is bounded below a certain threshold. We elucidate some interesting connections between entanglement and synchronization and, finally, discuss an application based on quantum optomechanical systems.
authors.affiliation: NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, I-56127 Pisa, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Mari
authors.affiliation: NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, I-56127 Pisa, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Farace
authors.affiliation: Département de Physique, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada and Department of Physics, McGill University, Montreal, Quebec H3A 2T8, Canada.
authors.forename: N
authors.initials: N
authors.lastname: Didier
authors.affiliation: NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, I-56127 Pisa, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Giovannetti
authors.affiliation: NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, I-56127 Pisa, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Fazio