49,375 research outputs found

    Robust Preparation of GHZ and W States of Three Distant Atoms

    Full text link
    Schemes to generate Greenberger-Horne-Zeilinger(GHZ) and W states of three distant atoms are proposed in this paper. The schemes use the effects of quantum statistics of indistinguishable photons emitted by the atoms inside optical cavities. The advantages of the schemes are their robustness against detection inefficiency and asynchronous emission of the photons. Moreover, in Lamb-Dicke limit, the schemes do not require simultaneous click of the detectors, this makes the schemes more realizable in experiments.Comment: 5 pages, 1 fiure. Phys. Rev. A 75, 044301 (2007

    Statefinder Parameters for Five-Dimensional Cosmology

    Full text link
    We study the statefinder parameter in the five-dimensional big bounce model, and apply it to differentiate the attractor solutions of quintessence and phantom field. It is found that the evolving trajectories of these two attractor solutions in the statefinder parameters plane are quite different, and that are different from the statefinder trajectories of other dark energy models.Comment: 8 pages, 12 figures. accepted by MPL

    Crystal growth and quantum oscillations in the topological chiral semimetal CoSi

    Get PDF
    We survey the electrical transport properties of the single-crystalline, topological chiral semimetal CoSi which was grown via different methods. High-quality CoSi single crystals were found in the growth from tellurium solution. The sample's high carrier mobility enables us to observe, for the first time, quantum oscillations (QOs) in its thermoelectrical signals. Our analysis of QOs reveals two spherical Fermi surfaces around the R point in the Brillouin zone corner. The extracted Berry phases of these electron orbits are consistent with the -2 chiral charge as reported in DFT calculations. Detailed analysis on the QOs reveals that the spin-orbit coupling induced band-splitting is less than 2 meV near the Fermi level, one order of magnitude smaller than our DFT calculation result. We also report the phonon-drag induced large Nernst effect in CoSi at intermediate temperatures

    Ultraviolet photonic crystal laser

    Get PDF
    We fabricated two dimensional photonic crystal structures in zinc oxide films with focused ion beam etching. Lasing is realized in the near ultraviolet frequency at room temperature under optical pumping. From the measurement of lasing frequency and spatial profile of the lasing modes, as well as the photonic band structure calculation, we conclude that lasing occurs in the strongly localized defect modes near the edges of photonic band gap. These defect modes originate from the structure disorder unintentionally introduced during the fabrication process.Comment: 4 pages, 4 figure

    Alfven seismic vibrations of crustal solid-state plasma in quaking paramagnetic neutron star

    Get PDF
    Magneto-solid-mechanical model of two-component, core-crust, paramagnetic neutron star responding to quake-induced perturbation by differentially rotational, torsional, oscillations of crustal electron-nuclear solid-state plasma about axis of magnetic field frozen in the immobile paramagnetic core is developed. Particular attention is given to the node-free torsional crust-against-core vibrations under combined action of Lorentz magnetic and Hooke's elastic forces; the damping is attributed to Newtonian force of shear viscose stresses in crustal solid-state plasma. The spectral formulae for the frequency and lifetime of this toroidal mode are derived in analytic form and discussed in the context of quasi-periodic oscillations of the X-ray outburst flux from quaking magnetars. The application of obtained theoretical spectra to modal analysis of available data on frequencies of oscillating outburst emission suggests that detected variability is the manifestation of crustal Alfven's seismic vibrations restored by Lorentz force of magnetic field stresses.Comment: 10 pages, 10 figure

    Three-Dimensional Modelling and Simulation of the Ice Accretion Process on Aircraft Wings

    Get PDF
    © 2018 Chang S, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.In this article, a new computational method for the three-dimensional (3D) ice accretion analysis on an aircraft wing is formulated and validated. The two-phase flow field is calculated based on Eulerian-Eulerian approach using standard dispersed turbulence model and second order upwind differencing with the aid of commercial software Fluent, and the corresponding local droplet collection efficiency, convective heat transfer coefficient, freezing fraction and surface temperature are obtained. The classical Messinger model is modified to be capable of describing 3D thermodynamic characteristics of ice accretion. Considering effects of runback water, which is along chordwise and spanwise direction, an extended Messinger method is employed for the prediction of the 3D ice accretion rates. Validation of the newly developed model is carried out through comparisons with available experimental ice shape and LEWICE codes over a GLC-305 wing under both rime and glaze icing conditions. Results show that good agreement is achieved between the current computational ice shapes and the compared results. Further calculations based on the proposed method over a M6 wing under different test conditions are numerically demonstrated.Peer reviewedFinal Published versio

    Effect of nitrogen, phosphorous, potassium, plant growth regulator and artificial lodging on grain yield and grain quality of a landrace of barley

    Full text link
    Landraces of different crops are still preferred due to their stable yields under low inputs and adverse climatic conditions to which most modern varieties are not adapted. In the UK, a landrace of barley called Bere is currently grown in extreme climatic conditions of Orkney to which most of the modern varieties are not adapted. Although this landrace is probably the oldest barley under cultivation in the UK, very little research has been conducted. In this paper the effects of nitrogen, phosphorous, potassium, plant growth regulator and artificial lodging on grain yield and quality of Bere were investigated in the Orkney\u27s short growing season. Higher nitrogen application resulted in a higher lodging incidence but grain yield was not reduced by the severity of lodging. The artificial lodging applied at Zadoks growth stage 77 resulted in the greatest yield losses which indicated that control measures may be required to avoid lodging at this critical growth stage. Phosphorous and potassium had no significant effect on lodging resistance. Whilst plant growth regulator improved lodging resistance it was less effective in controlling lodging at the highest nitrogen level (90 kg ha-1). The trials indicated that higher level of N caused marginal increase in grain yield when nitrogen level was raised from 45 kg to 90 kg ha-1. This tended to suggest the use of medium N-level (45 kg N ha-1) for producing Bere. Plant growth regulator increased lodging resistance but had an inconsistent effect on grain yield. This study recommended the use of plant growth regulator as a means of easing harvesting rather than for enhancing yield and quality. The study concluded that phosphorous and potassium could be used to improve disease resistance and grain yield but not for lodging control
    corecore