title: Inseparability criterion for continuous variable systems
abstract: An inseparability criterion based on the total variance of a pair of Einstein-Podolsky-Rosen type operators is proposed for continuous variable systems. The criterion provides a sufficient condition for entanglement of any two-party continuous variable states. Furthermore, for all Gaussian states, this criterion turns out to be a necessary and sufficient condition for inseparability.
authors.affiliation: Institut fur Theoretische Physik, Universitat Innsbruck, A-6020 Innsbruck, Austria and Laboratory of Quantum Communication and Quantum Computation, University of Science and Technology of China, Hefei 230026, China.
authors.initials: LM
authors.lastname: Duan
authors.initials: G
authors.lastname: Giedke
authors.initials: JI
authors.lastname: Cirac
authors.initials: P
authors.lastname: Zoller