19,107 research outputs found

    Photovoltage Detection of Edge Magnetoplasmon Oscillations and Giant Magnetoplasmon Resonances in A Two-Dimensional Hole System

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    In our high mobility p-type AlGaAs/GaAs two-dimensional hole samples, we originally observe the B-periodic oscillation induced by microwave (MW) in photovoltage (PV) measurements. In the frequency range of our measurements (5 - 40 GHz), the period ({\Delta}B) is inversely proportional to the microwave frequency (f). The distinct oscillations come from the edge magnetoplasmon (EMP) in the high quality heavy hole system. In our hole sample with a very large effective mass, the observation of the EMP oscillations is in neither the low frequency limit nor the high frequency limit, and the damping of the EMP oscillations is very weak under high magnetic fields. Simultaneously, we observe the giant plasmon resonance signals in our measurements on the shallow two-dimensional hole system (2DHS)

    The explicit expression of the fugacity for weakly interacting Bose and Fermi gases

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    In this paper, we calculate the explicit expression for the fugacity for two- and three-dimensional weakly interacting Bose and Fermi gases from their equations of state in isochoric and isobaric processes, respectively, based on the mathematical result of the boundary problem of analytic functions --- the homogeneous Riemann-Hilbert problem. We also discuss the Bose-Einstein condensation phase transition of three-dimensional hard-sphere Bose gases.Comment: 24 pages, 9 figure

    Functional kernel estimators of conditional extreme quantiles

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    We address the estimation of "extreme" conditional quantiles i.e. when their order converges to one as the sample size increases. Conditions on the rate of convergence of their order to one are provided to obtain asymptotically Gaussian distributed kernel estimators. A Weissman-type estimator and kernel estimators of the conditional tail-index are derived, permitting to estimate extreme conditional quantiles of arbitrary order.Comment: arXiv admin note: text overlap with arXiv:1107.226

    Dissipationless Anomalous Hall Current in Fe100x(SiO2)xFe_{100-x}(SiO_2)_x Films

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    The observation of dissipationless anomalous Hall current is one of the experimental evidences to confirm the intrinsic origin of anomalous Hall effect. To study the origin of anomalous Hall effect in iron, Fe100x_{100-x}(SiO2_{2})x_{x} granular films with volume fraction of SiO2_{2} 0\le x \le 40.51 were fabricated using co-sputtering. Hall and longitudinal resistivities were measured in the temperature range 5 to 350 K with magnetic fields up to 5 Tesla. As x increased from 0 to 40.51, the anomalous Hall resistivity and longitudinal resistivity increased about 4 and 3 orders in magnitude, respectively. Analysis of the results revealed that the normalized anomalous Hall conductivity is a constant for all the samples, the evidence of dissipationless anomalous Hall current in Fe.Comment: 17 pages, 5 figures; http://link.aps.org/doi/10.1103/PhysRevB.83.20531

    Solar Water Splitting Cells

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    Structural Characterization of Rapid Thermal Oxidized Si\u3csub\u3e1−x−y\u3c/sub\u3eGe\u3csub\u3ex\u3c/sub\u3eC\u3csub\u3ey\u3c/sub\u3e Alloy Films Grown by Rapid Thermal Chemical Vapor Deposition

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    The structural properties of as-grown and rapid thermal oxidized Si1−x−yGexCy epitaxial layers have been examined using a combination of infrared, x-ray photoelectron, x-ray diffraction, secondary ion mass spectroscopy, and Raman spectroscopy techniques. Carbon incorporation into the Si1−x−yGexCy system can lead to compressive or tensile strain in the film. The structural properties of the oxidized Si1−x−yGexCy film depend on the type of strain (i.e., carbon concentration) of the as-prepared film. For compressive or fully compensated films, the oxidation process drastically reduces the carbon content so that the oxidized films closely resemble to Si1−xGex films. For tensile films, two broad regions, one with carbon content higher and the other lower than that required for full strain compensation, coexist in the oxidized films

    Spectroscopic ellipsometry and electrical studies of as-grown and rapid thermal oxidized Si\u3csub\u3e1−x−y\u3c/sub\u3eGe\u3csub\u3ex\u3c/sub\u3eC\u3csub\u3ey\u3c/sub\u3e films

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    Transmission electron microscopy results showed the formation of SiC precipitation in a rapid thermally oxidized (RTO) Si1−x−yGexCy sample with high-C content. The spectroscopic ellipsometry results showed that the E1 gap increased and E2 gap decreased as the C concentration increased. For the oxidized samples, the amplitude of the E2 transitions reduced rapidly and the E1 transition shifted to a lower energy. The reduction in the E2 transitions was due to the presence of the oxide layer. A high-Ge content layer and the low-C content in the RTO films accounted for the E1 shift to lower energy. The electrical measurements showed that RTO at 800 °C did not improve the oxide quality as compared to 1000 °C
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