57,376 research outputs found

    First principles study of electronic transport through a Cu(111)|graphene junction

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    We report first principles investigations of the nonequilibrium transport properties of a Cu(111)|graphene interface. The Cu(111) electrode is found to induce a transmission minimum (TM) located -0.68eV below the Fermi level, a feature originating from the Cu-induced charge transfer resulting in n-type doped graphene with the Dirac point coinciding with the TM. An applied bias voltage shifts the n-graphene TM relative to the pure graphene TM and leads to a distinctive peak in the differential conductance indicating the doping level, a characteristic not observed in pure graphene.Comment: 3 pages, 3 figure

    Light-front wavefunction dependence of the quark recombination

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    We present an extension of the recombination formalism to analyze the effects from the variation of the hadron wavefunctions. The hadron spectra are sensitive to the shape of the wavefunctions. However, when we fit the wavefunction parameters to the physical observables, such as the average charge radius, the final spectra are very similar each other. We discuss our numerical results in comparison with the published PHENIX and STAR data at RHIC. In the hadron spectra, the recombination of thermal partons dominates at intermediate transverse momentum (PTP_{T} = 2 \sim 5 GeV), and the fragmentation dominates at high PTP_{T} (>> 5 GeV). The yield ratios and the nuclear modification factors for various hadron species are also estimated and compared to the experimental data. We present a new prediction on pˉ/p\bar{p}/p and K/K+K^{-}/K^{+} ratios, including the jet quenching effects to the fragmentation mechanism.Comment: 26 pages, 7 figure

    Double occupancies in confined attractive fermions on optical lattices

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    We perform a numerical study of a one-dimensional Fermion-Hubbard model in harmonic traps within the Thomas-Fermi approximation based on the exact Bethe-ansatz solution. The ρU/t\rho-U/t phase diagram is shown for the systems of attractive interactions (ρ\rho is the characteristic density and U/tU/t the interaction strength scaled in units of the hopping parameter.). We study the double occupancy, the local central density and their derivatives. Their roles are discussed in details in detecting the composite phases induced by the trapping potential.Comment: 4 pages, 4 figures, submitte
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