Browsing by Author "Dai, H."

Now showing 1 - 3 of 3
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    Coulomb Gap and Correlated Vortex Pinning in Superconductors
    Täuber, Uwe C.; Dai, H.; Nelson, D.; Lieber, C. (1995-06-19)
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    Experimentally engineering the edge termination of graphene nanoribbons
    Zhang, X.; Yazyev, O. V.; Feng, J.; Xie, L.; Tao, C.; Chen, Y. C.; Jiao, L.; Pedramrazi, Z.; Zettl, A.; Louie, S. G.; Dai, H.; Crommie, M. F. (2013-01-22)
    The edges of graphene nanoribbons (GNRs) have attracted much interest due to their potentially strong influence on GNR electronic and magnetic properties. Here we report the ability to engineer the microscopic edge termination of high-quality GNRs via hydrogen plasma etching. Using a combination of high-resolution scanning tunneling microscopy and first-principles calculations, we have determined the exact atomic structure of plasma-etched GNR edges and established the chemical nature of terminating functional groups for zigzag, armchair, and chiral edge orientations. We find that the edges of hydrogen-plasma-etched GNRs are generally flat, free of structural reconstructions, and terminated by hydrogen atoms with no rehybridization of the outermost carbon edge atoms. Both zigzag and chiral edges show the presence of edge states.
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    Probing electron-argon scattering for liquid-argon based neutrino-oscillation program
    Pandey, V.; Abrams, D.; Alsalmi, S.; Ankowski, Artur M.; Bane, J.; Benhar, Omar; Dai, H.; Day, D. B.; Higinbotham, D. W.; Mariani, Camillo; Murphy, M.; Nguyen, D. (2017-11-05)
    The electron scattering has been a vital tool to study the properties of the target nucleus for over five decades. Though, the particular interest on 40Ar nucleus stemmed from the progress in the accelerator-based neutrino-oscillation experiments. The complexity of nuclei comprising the detectors and their weak response turned out to be one of the major hurdles in the quest of achieving unprecedented precision in these experiments. The challenges are further magnified by the use of Liquid Argon Time Projection Chambers (LArTPCs) in the short- (SBN) and long-baseline (DUNE) neutrino program, with almost non-existence electron-argon scattering data and hence with no empirical basis to test and develop nuclear models for 40Ar. In light of these challenges, an electron-argon experiment, E12-14-012, was proposed at Jefferson Lab. The experiment has recently successfully completed collecting data for (e,e'p) and (e,e') processes, not just on 40Ar but also on 48Ti, and 12C targets. While the analysis is running with full steam, in this contribution, we present a brief overview of the experiment.