784 research outputs found

    Scaling the neutral atom Rydberg gate quantum computer by collective encoding in Holmium atoms

    Full text link
    We discuss a method for scaling a neutral atom Rydberg gate quantum processor to a large number of qubits. Limits are derived showing that the number of qubits that can be directly connected by entangling gates with errors at the 10310^{-3} level using long range Rydberg interactions between sites in an optical lattice, without mechanical motion or swap chains, is about 500 in two dimensions and 7500 in three dimensions. A scaling factor of 60 at a smaller number of sites can be obtained using collective register encoding in the hyperfine ground states of the rare earth atom Holmium. We present a detailed analysis of operation of the 60 qubit register in Holmium. Combining a lattice of multi-qubit ensembles with collective encoding results in a feasible design for a 1000 qubit fully connected quantum processor.Comment: 6 figure

    Elastic ppˉ\rm{p\bar p} Scattering Amplitude at 1.8 TeV and Determination of Total Cross Section

    Full text link
    The data on ppˉ\mathrm{\bar p} elastic scattering at 1.8 and 1.96 TeV are analysed in terms of real and imaginary amplitudes, in a treatment with high accuracy, covering the whole t-range and satisfying the expectation of dispersion relation for amplitudes and for slopes. A method is introduced for determination of the total cross section and the other forward scattering parameters and to check compatibility of E-710, CDF and the recent D0 data. Slopes BRB_R and BI B_I of the real and imaginary amplitudes, treated as independent quantities, influence the amplitudes in the whole t-range and are important for the determination of the total cross section. The amplitudes are fully constructed, and a prediction is made of a marked dip in dσ/dt d\sigma/dt in the t|t| range 3 - 5 GeV2^2 due to the universal contribution of the process of three gluon exchange.Comment: 22 pages, 12 figures, 2 table

    A Seriuos Academic Work

    Get PDF
    С.А. Кравченко «Социологический толковый англо-русский словарь». М.: МГИМО(У) МИД России, 2012. 690 с. (Серия «Энциклопедии и словари МГИМО(У)»)

    Langmuir-Schaefer films of a polyaniline-gold nanoparticle composite material for applications in organic memristive devices

    Get PDF
    Langmuir-Shaefer films of a polyaniline-gold nanoparticle composite were fabricated and characterized. The thickness of each deposited monolayer, determined with AFM, was found to be about 0.8 nm. The film morphology was studied by SEM, revealing the presence of embedded spherical-shaped gold nanoparticles of about 5-10 nm in diameter. The fabricated films were used as the active channel of the organic memristor. Its electric characterisation has revealed new phenomena, such as an increased working voltage range and sigmoidal voltage current characteristics that were connected to the charge trappin

    Renormalization Group Theory for a Perturbed KdV Equation

    Full text link
    We show that renormalization group(RG) theory can be used to give an analytic description of the evolution of a perturbed KdV equation. The equations describing the deformation of its shape as the effect of perturbation are RG equations. The RG approach may be simpler than inverse scattering theory(IST) and another approaches, because it dose not rely on any knowledge of IST and it is very concise and easy to understand. To the best of our knowledge, this is the first time that RG has been used in this way for the perturbed soliton dynamics.Comment: 4 pages, no figure, revte

    Formation of Nanoclusters and Nanopillars in Nonequilibrium Surface Growth for Catalysis Applications: Growth by Diffusional Transport of Matter in Solution Synthesis

    Full text link
    Growth of nanoclusters and nanopillars is considered in a model of surface deposition of building blocks (atoms) diffusionally transported from solution to the forming surface structure. Processes of surface restructuring are also accounted for in the model, which then yields morphologies of interest in catalysis applications. Kinetic Monte Carlo numerical approach is utilized to explore the emergence of FCC-symmetry surface features in Pt-type metal nanostructures. Available results exemplify evaluation of the fraction of the resulting active sites with desirable properties for catalysis, such as (111)-like coordination, as well as suggest optimal growth regimes

    Photon echoes generated by reversing magnetic field gradients in a rubidium vapour

    Full text link
    We propose a photon echo quantum memory scheme using detuned Raman coupling to long lived ground states. In contrast to previous 3-level schemes based on controlled reversible inhomogeneous broadening that use sequences of π\pi-pulses, the scheme does not require accurate control of the coupling dynamics to the ground states. We present a proof of principle experimental realization of our proposal using rubidium atoms in a warm vapour cell. The Raman resonance line is broadened using a magnetic field that varies linearly along the direction of light propagation. Inverting the magnetic field gradient rephases the atomic dipoles and re-emits the light pulse in the forward direction

    Spectrum Estimation of Density Operators with Alkaline-Earth Atoms

    Get PDF
    We show that Ramsey spectroscopy of fermionic alkaline-earth atoms in a square-well trap provides an efficient and accurate estimate for the eigenspectrum of a density matrix whose n copies are stored in the nuclear spins of n such atoms. This spectrum estimation is enabled by the high symmetry of the interaction Hamiltonian, dictated, in turn, by the decoupling of the nuclear spin from the electrons and by the shape of the square-well trap. Practical performance of this procedure and its potential applications to quantum computing and time keeping with alkaline-earth atoms are discussed
    corecore