1,016 research outputs found

    Anomalous Hall effect in field-effect structures of (Ga,Mn)As

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    The anomalous Hall effect in metal-insulator-semiconductor structures having thin (Ga,Mn)As layers as a channel has been studied in a wide range of Mn and hole densities changed by the gate electric field. Strong and unanticipated temperature dependence, including a change of sign, of the anomalous Hall conductance σxy\sigma_{xy} has been found in samples with the highest Curie temperatures. For more disordered channels, the scaling relation between σxy\sigma_{xy} and σxx\sigma_{xx}, similar to the one observed previously for thicker samples, is recovered.Comment: 5 pages, 5 figure

    Bias dependence of tunneling-electron-induced molecular fluorescence from porphyrin films on noble-metal substrates

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    We investigated scanning tunneling microscope (STM)-excited luminescence from porphyrin (PhTPP and H2TPP) thin films on metal substrate (Au and Ag) under ambient conditions. Molecular fluorescence similar to the corresponding photoluminescence was observed from PhTPP/Au and H2TPP/Ag at both STM bias polarities. We found that at the same experimental condition and parameters, the STM-induced luminescence intensities of maxima peak are similar for PhTPP and H2TPP but weaker by a factor of about 4 than that for H2TBPP which we studied previously, probably due to fluorescence quenching by aggregation. The polarity dependence and the bias voltage dependence of the fluorescence intensity for the PhTPP/Au were similar to that for the respective pristine metal. These facts support our proposal that intense molecular fluorescence from porphyrin film on the noble metals is a result of the enhancement of molecular excitation by substrate surface plasmons

    STM fluorescence of porphyrin enhanced by a strong plasmonic field and its nanoscale confinement in an STM cavity

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    We have investigated scanning tunneling microscope-induced luminescence STML from porphyrin molecules by varying the tip PtIr, Ag, and Au/substrate Pt, Ag, Au, and indium tin oxide combinations. Strong molecular fluorescence by highest-occupied molecular orbital and lowest-unoccupied molecular orbital transition comparable to plasmon-mediated light is emitted only when both the substrate and the tip are metals but not in other cases. Along with calculations of relative electromagnetic-field powers in the tip-substrate gaps, the enhancement of STML from molecules can be interpreted in terms of the strong plasmon field and its confinement in an STM cavity. We also find rather strong energy-forbidden fluorescence of porphyrin in an Au-tip/porphyrin/Au cavity that occurs under the extremely strong field in the plasmonic nanocavity

    Direct k-space mapping of the electronic structure in an oxide-oxide interface

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    The interface between LaAlO3 and SrTiO3 hosts a two-dimensional electron system of itinerant carriers, although both oxides are band insulators. Interface ferromagnetism coexisting with superconductivity has been found and attributed to local moments. Experimentally, it has been established that Ti 3d electrons are confined to the interface. Using soft x-ray angle-resolved resonant photoelectron spectroscopy we have directly mapped the interface states in k-space. Our data demonstrate a charge dichotomy. A mobile fraction contributes to Fermi surface sheets, whereas a localized portion at higher binding energies is tentatively attributed to electrons trapped by O-vacancies in the SrTiO3. While photovoltage effects in the polar LaAlO3 layers cannot be excluded, the apparent absence of surface-related Fermi surface sheets could also be fully reconciled in a recently proposed electronic reconstruction picture where the built-in potential in the LaAlO3 is compensated by surface O-vacancies serving also as charge reservoir.Comment: 8 pages, 6 figures, incl. Supplemental Informatio

    A CROSS-SECTIONAL STUDY OF GENDER DIFFERENCES IN PULLING STRENGTH OF TOW FOR JAPANESE ELEMENTARY SCHOOL CHILDREN

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    The aim of this study was to obtain the data of gender differences of pulling strength during experimentally executed TOW for Japanese elementary school children. In mean back strength, gender difference was small from 1st grade to 4th grade, but on 5th and 6th grade, gender difference became large. In mean pulling strength, gender difference was large in 5th and 6th grade. But no tendency was found from 1st grade to 4th grade. In male children, sum of pulling strength increases substantially when the grade changes from 4th to 5th. But pulling strength tended to grow constantly. On the other hand, in female children, sum of pulling strength increases substantially when the grade changes from 2nd to 3rd. And from 4th to 6th, sum of back strength and rope tension were very close to each other. Results suggested that though male children get grow for muscles, female children get motor function more than male children

    KINEMATICS ANALYSIS OF TWO STYLES OF BOW FOR MARTIAL ARTISTS AND AVARAGE STUDENTS

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    The aim of this study was to conduct operating analysis of two styles of bow (RITSUREI and ZAREI) for martial artists and average students, and to compare their kinematics characteristic of. Subjects of this study were healthy men (n=33) who were martial artist group (MA, n=18) and average student group (AS, n=15). Subjects conducted RITSUREI and ZAREI three times each. Results of paired t-test, on angular degree parameter of RITSUREI, MA made smaller angular degree of the upper limbs and angular degree of the neck than that of AS. regarding time parameter components, the total time of ZAREI, from beginning of it to stopping, from stopping of it to end, and from beginning of RITSUREI to stopping were significantly shorter than that of AS. MA made several characteristic shown in text. BUDO bow is regarded as practical bow even in social rule when bow teaching is conducte
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