title: Entanglement purification of gaussian continuous variable quantum states
abstract: We describe an entanglement purification protocol to generate maximally entangled states with high efficiencies from two-mode squeezed states or from mixed Gaussian continuous entangled states. The protocol relies on a local quantum nondemolition measurement of the total excitation number of several continuous variable entangled pairs. We propose an optical scheme to do this kind of measurement using cavity enhanced cross-Kerr interactions.
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