323 research outputs found
Experimental Quantum Teleportation with a 3-Bell-state Analyzer
We present a Bell-state analyzer for time-bin qubits allowing the detection
of three out of four Bell-states with linear optics, two detectors and no
auxiliary photons. The theoretical success rate of this scheme is 50%. A
teleportation experiment was performed to demonstrate its functionality. We
also present a teleportation experiment with a Fidelity larger than the cloning
limit of F=5/6.Comment: 11 pages, 14 figure
Long distance entanglement swapping with photons from separated sources
We report the first experimental realization of entanglement swapping over
large distances in optical fibers. Two photons separated by more than two km of
optical fibers are entangled, although they never directly interacted. We use
two pairs of time-bin entangled qubits created in spatially separated sources
and carried by photons at telecommunication wavelengths. A partial Bell state
measurement is performed with one photon from each pair which projects the two
remaining photons, formerly independent onto an entangled state. A visibility
high enough to violate a Bell inequality is reported, after both photons have
each travelled through 1.1 km of optical fiber.Comment: 4 pages, 3 figures, submitte
Quantum Teleportation with a 3-Bell-state Analyzer
We present a novel Bell-state analyzer for time-bin qubits allowing the
detection of three out of four Bell-states with linear optics, only two
detectors and no auxiliary photons. The theoretical success rate of this scheme
is 50%. A teleportation experiment was performed to demonstrate its
functionality. We also present a teleportation experiment with a fidelity
larger than the cloning limit.Comment: 4 pages, 6 figure
Statistical models for quantifying diagnostic accuracy with multiple lesions per patient
We propose random-effects models to summarize and quantify the accuracy of the diagnosis of multiple lesions on a single image without assuming independence between lesions. The number of false-positive lesions was assumed to be distributed as a Poisson mixture, and the proportion of true-positive lesions was assumed to be distributed as a binomial mixture. We considered univariate and bivariate, both parametric and nonparametric mixture models. We applied our tools to simulated data and data of a study assessing diagnostic accuracy of virtual colonography with computed tomography in 200 patients suspected of having one or more polyps
Teelt van mais op klei-op-veengrond. Bemesting en grondbewerking
rapport bevat de resultaten van veldproeven op het gebied van bemesting en grondbewerking, die in de periode 1997-1999 door proefbedrijf Zegveld van het Praktijkonderzoek Rundvee, Schapen en Paarden (PR) zijn uitgevoerd
Controlled Quantum Secret Sharing
We present a new protocol in which a secret multiqubit quantum state
is shared by players and controllers, where
is the encoding state of a quantum secret sharing scheme. The players may be
considered as field agents responsible for carrying out a task, using the
secret information encrypted in , while the controllers are
superiors who decide if and when the task should be carried out and who to do
it. Our protocol only requires ancillary Bell states and Bell-basis
measurements.Comment: 6 pages, 0 figure, RevTeX4; published version with minor change
Space-like Separation in a Bell Test assuming Gravitationally Induced Collapses
We report on a Bell experiment with space-like separation assuming that the
measurement time is related to gravity-induced state reduction. Two energy-time
entangled photons are sent through optical fibers and directed into unbalanced
interferometers at two receiving stations separated by 18 km. At each station,
the detection of a photon triggers the displacement of a macroscopic mass. The
timing ensures space-like separation from the moment a photon enters its
interferometer until the mass has moved. 2-photon interference fringes with a
visibility of up to 90.5% are obtained, leading to a violation of Bell
inequality
The santalene synthase from <i>Cinnamomum camphora</i>: Reconstruction of a sesquiterpene synthase from a monoterpene synthase
Multivariate random effects meta-analysis of diagnostic tests with multiple thresholds
Background. Bivariate random effects meta-analysis of diagnostic tests is becoming a well established approach when studies present one two-by-two table or one pair of sensitivity and specificity. When studies present multiple thresholds for test positivity, usually meta-analysts reduce the data to a two-by-two table or take one threshold value at a time and apply the well developed meta-analytic approaches. However, this approach does not fully exploi
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