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CreatorTitleDescriptionSubjectDate
1 Liu, FengCoulomb sink: a novel Coulomb effect on coarsening of metal nanoclusters on semiconductor surfacesWe propose the concept of a ‘‘Coulomb sink'' to elucidate the effect of Coulomb charging on coarsening of metal mesas grown on semiconductor surfaces.We show that a charged mesa, due to its reduced chemical potential, acts as a Coulomb sink and grows at the expense of neighboring neutral mesas. ...Coulomb sink; Coulomb effect; Metal nanoclusters; Semiconductor surface; Pb mesas2004-09
2 Gondolo, PaoloEffects of the Sagittarius dwarf tidal stream on dark matter detectorsThe Sagittarius dwarf tidal stream may be showering dark matter onto the solar neighborhood, which can change the results and interpretation of direct detection searches for weakly interacting massive particles (WIMPs). Stars in the stream may already have been detected in the solar neighborhood, an...Sagittarius dwarf galaxy; Sgr stream; WIMP; Weakly interacting massive particles2004-03
3 Lupton, John MarkExperimental evidence for exciton scaling effects in self-assembled molecular wiresResonant Rayleigh scattering from self-assembled one-dimensional molecular J-aggregate wires reveals a distinct dependence of the exciton energy on the width of lateral extension. For the J aggregates used in this study, strong in-line dipole coupling leads to a delocalization of the exciton wave fu...Exciton scaling effects; Molecular wires; J-aggregate wires; Quantum wires2004-12
4 Liu, FengGeometric constant defining shape transitions of carbon nanotubes under pressureWe demonstrate that when a single-walled carbon nanotube is under pressure it undergoes a series of shape transitions, first transforming from a circle to an oval and then from an oval to a peanut. Most remarkably, the ratio of the area of the tube cross sections at the second transition over that ...Geometric constant; Shape transitions; Carbon nanotubes; Pressure2004-03
5 DeTar, CarletonHigh-precision lattice QCD confronts experimentThe recently developed Symanzik-improved staggered-quark discretization allows unquenched lattice-QCD simulations with much smaller (and more realistic) quark masses than previously possible. To test this formalism, we compare experiment with a variety of nonperturbative calculations in QCD draw...Staggered quarks2004-01
6 Liu, FengLocal strain-mediated chemical potential control of quantum dot self-organization in heteroepitaxyFrom observations of self-assembly of Ge quantum dots directed by substrate morphology, we propose the concept of control of ordering in heteroepitaxy by a local strain-mediated surface chemical potential. Using quite simple lithography, we demonstrate directed quantum dot ordering. The strain part ...Self-organization; Heteroepitaxy; Chemical potential control; Ge quantum dots2004-01
7 Kieda, David B.; Bergman, Douglas R.; Sokolsky, PierreMeasurement of the flux of ultrahigh energy cosmic rays from monocular observations by the high resolution fly's eye experimentWe have measured the cosmic ray spectrum above 10^172 eV using the two air-fluorescence detectors of the High Resolution Fly's Eye observatory operating in monocular mode.We describe the detector, phototube, and atmospheric calibrations, as well as the analysis techniques for the two detectors.We ...High Resolution Fly's Eye; Ultrahigh energy cosmic rays2004-04
8 Sokolsky, PierreMeasurement of the flux of ultrahigh energy cosmic rays from monocular observations by the High Resolution Fly's Eye experimentWe have measured the cosmic ray spectrum above 1017.2 eV using the two air-fluorescence detectors of the High Resolution Fly's Eye observatory operating in monocular mode.We describe the detector, phototube, and atmospheric calibrations, as well as the analysis techniques for the two detectors.We fi...Extensive air showers; Fluorescence; Energy spectrum2004-04
9 Lupton, John MarkMonitoring surface charge movement in single elongated semiconductor nanocrystalsWe demonstrate a universal correlation between the spectral linewidth and position of the excitonic transition in the spectral jitter observed from single elongated colloidal quantum dots. Breaking the symmetry of electron and hole confinement as well as of the spatial directions for surface charge ...Surface charge movement; Spectral linewidth; Excitonic transition; Spectral jitter; Colloidal nanocrystals2004-10
10 Liu, FengSelf-organized quantum-wire lattice via step flow growth of a short-period superlatticeWe develop a theoretical model for step flow growth of multilayer films, taking into account the interlayer step-step interaction induced by misfit strain.We apply the model to simulate the growth of strain-compensated short-period superlattices. Step-bunch ordering improves in successive layers, le...Quantum-wire lattice; Short-period superlattice; Step flow growth2004-06
11 Mishchenko, EugeneSpin current and polarization in impure two-dimensional electron systems with spin-orbit couplingWe derive the transport equations for two-dimensional electron systems with Rashba spin-orbit interaction and short-range spin-independent disorder. In the limit of slow spatial variations, we obtain coupled diffusion equations for the electron density and spin. Using these equations we calculate el...Spin-orbit coupling; Spin current2004-11
12 Gerton, JordanTip-enhanced fluorescence microscopy at 10 nanometer resolutionWe demonstrate unambiguously that the field enhancement near the apex of a laser-illuminated silicon tip decays according to a power law that is moderated by a single parameter characterizing the tip sharpness. Oscillating the probe in intermittent contact with a semiconductor nanocrystal strongly...2004-10
13 Vardeny, Zeev ValentineUltrafast spectroscopy of excitons in single-walled carbon nanotubesWe studied the femtosecond dynamics of photoexcitations in films containing semiconducting and metallic single-walled carbon nanotubes (SWNTs), using various pump-probe wavelengths and intensities.We found that confined excitons and charge carriers with subpicosecond dynamics dominate the ultrafas...Ultrafast spectroscopy; Excitons; Single-walled carbon nanotubes; SWNT2004-01
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