301 - 325 of 924
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301 Williams, Clayton C.Scanning thermal profilerA new high-resolution profilometer has been demonstrated based upon a noncontacting nearfield thermal probe. The thermal probe consists of a thermocouple sensor with dimensions approaching 100 nm. Profiling is achieved by scanning the heated sensor above but close to the surface of a solid. The con...Thermal probe; Scanning thermal profiler1986
302 DeTar, C.Locality of the fourth root of staggard fermion determinant in the interacting caseThe fourth root approximation in LQCD simulations with dynamical staggered fermions requires justification. We test its validity numerically in the interacting theory in a renormalization group framework.Physics; Renormalization2005-09-29
303 DeTar, CarletonChiral logs with staggered fermionsWe compute chiral logarithms in the presence of "taste" symmetry breaking of staggered fermions. The lagrangian of Lee and Sharpe is generalized and then used to calculate the logs in π and K masses. We correct an error in Ref. [1]; the issue turns out to have implications for the comparison with ...Staggered fermions; Chiral logs2003-05
304 Williams, Clayton C.Lateral dopant profiling with 200 nm resolution by scanning capacitance microscopyMeasurement of dopant density in silicon with lateral resolution on the 200 nm scale has been demonstrated with a near-field capacitance technique. The technique is based upon the measurement of local capacitance between a 100 nm tip and a semiconducting surface. Lateral dopant imaging is achieved b...Dopant profile; Doping density; Scanning capacitance microscopy1989
305 Wu, Yong-ShiIntegrable spin chain and operator mixing in N = 1,2 supersymmetric theoriesWe study operator mixing, due to planar one-loop corrections, for composite operators in D = 4 supersymmetric theories. We present some N = 1, 2 Yang-Mills and Wess-Zumino models, in which the planar one-loop anomalous dimension matrix in the sector of holomorphic scalars is identified with the Hami...2004-04
306 Mattis, Daniel C.Solution of multiple scattering by finite iterationWe propose an iterative nonlinear solution to the general potential scattering problem in quantum mechanics. It is illustrated by the case of N2 localized scatterers of arbitrary strengths Vj located at arbitrary points Rj in an infinite lattice, for which we obtain the complete set of bound and sca...Bound states; Eigenstates1978-01
307 Gondolo, PaoloIndirect neutralino detection rates in neutrino telescopesNeutralinos annihilating in the center of the Sun or the Earth may give rise to a detectable signal of neutrinos. We derive the indirect detection rates for neutrino telescopes in the minimal supersymmetric extension of the standard model. We show that even after imposing all phenomenological and e...Neutralinos; Neutrino telescopes; Relic density; Annihilations1997-02
308 Vardeny, Zeev ValentineUnidirectional laser emission from ∏-conjugated polymer microcavities with broken symmetryWe report unidirectional laser emission from ∏-conjugated polymer microcavities with broken symmetry geometries such as spiral and microdisk containing a "line defect," in comparison with plain microdisk cavity having isotropic emission. We found that the laser emission directionality contrast ra...pi-conjugated polymers; Unidirectional laser emission; Microcavities; DOO-PPV; Poly(dioctyloxy) phenyl vinylene2007
309 Ailion, David CharlesLow cost high linearity solid state digital double boxcarIn this article, we describe a digital solid state double boxcar of infinite holding time and very high linearity. It uses a Hewlett-Packard (HP2212 A-M3) voltage-to-frequency converter (VFC) whose output is accumulated on a running counter, thereby providing signal averaging with an infinite holdin...High linearity; Boxcar; Instruments, Physics1969
310 Kieda, David B.; Sokolsky, PierreSearch for compact sources of cosmic photons above 200 TeVFrom April 1988 to February 1990 we used a two-level array of scintillators to search in the cosmic radiation for compact sources of y rays above 200 TeV. Counters on the surface measured the size and direction of extensive air showers while counters buried 3 m below ground measured their muon conte...Compact sources; Air showers1992-10
311 Symko, Orest GeorgeMagnetic memory of oil paintingsThe color in oil paints is obtained sometimes from magnetic minerals. This fact implies that oil paintings could present an intrinsic magnetization. Magnetic imaging of an oil painting consists in the measurement of magnetic flux related to the magnetization of the painting. In this report results o...Magnetic memory; Oil paintings; Authentication2007
312 Sokolsky, PierreObservation of the suppression of the flux of cosmic rays above 4×10^19eVThe energy spectrum of cosmic rays above 2.5 x 10^18 eV, derived from 20 000 events recorded at the Pierre Auger Observatory, is described. The spectral index γ of the particle flux, J∞ E-γ, at energies between 4 x 10^18 eV and 4 x 10^19 eV is 2.69 ± 0.02(stat) ± 0.06(syst), steepening to 4.2 ...Extensive air showers; Energy spectrum; Fluorescence; Suppression2008-08
313 Rogachev, AndreyDichotomy in short superconducting nanowires: thermal phase slippage vs. Coulomb blockadeQuasi-one-dimensional superconductors or nanowires exhibit a transition into a nonsuperconducting regime, as their diameter shrinks. We present measurements on ultrashort nanowires (∼40-190 nm long) in the vicinity of this quantum transition. Properties of all wires in the superconducting phase, e...Thermal phase slippage; Coulomb blockade2006-11-01
314 Lupton, John MarkOrigin of spectral broadening in amorphous π-conjugated amorphous semiconductorsWe present a study of the picosecond fluorescence dynamics of p-conjugated semiconducting organic dendrimers in the solid state. By varying the degree of branching within the dendrons, referred to as the dendrimer generation, a control of intermolecular spacing of the emissive core and therefore o...pi-conjugated polymers; pi-conjugated semiconductors; Spectral broadening; Solid state; Picosecond fluorescence dynamics2002-10
315 Wu, Yong-ShiMaster ward identity for nonlocal symmetries in D = 2 principal chiral modelsWe derive, in path integral approach, the (anomalous) master Ward identity associated with an infinite set of nonlocal conservation laws in two-dimensional principal chiral models.1997-11
316 Mattis, Daniel C.Theory of negative-mass cyclotron resonanceIn recent communications1'2 Dousmanis et al. suggest that the re-entrant energy contours of the heavy-hole bands in Ge and Si3 could contribute a negative resistivity component to the overall resistivity of these materials, possibly related to a nonequilibrium density of carriers in these re-ent...Cyclotron resonance; Steady state1959-07
317 Vardeny, Zeev Valentine; Gellermann, WernerLaser properties of luminescent conducting polymers in open resonatorsWe have investigated the lasing properties of several luminescent conducting polymers, i.e. DOO-PPV and the bi-substituted polyacetylenes PDPA-nBu, and PHJPA, dissolved in various polar and non-polar solvents. PP V polymers emit with high quantum efficiencies in broad emission bands centered in the ...Lasing; Amplified spontaneous emission; Spectral narrowing1997
318 Vardeny, Zeev ValentineOptical and magneto-optical studies of two-dimensional metallodielectric photonic crystals on cobalt filmsWe studied the optical transmission and magneto-optical effect through a subwavelength hole array fabricated on a ferromagnetic cobalt (Co) thin film in comparison to a control unperforated Co film having the same thickness. We found that the perforated film sustains extraordinary transmission bands...Metallodielectric photonic crystals; Cobalt films2004
319 Mattis, Daniel C.Short-range versus long-range order in a model binary alloyWe calculate the free energy of a linear binary metallic alloy using an exact transfer-matrix formalism. We obtain for the first time the electronic band structure when there is nonvanishing short-range order and calculate the temperature dependence of the short-range order parameter. Following Foo...Binary alloys; Density of state; Free energy1971-07
320 Gerton, JordanTip-enhanced fluorescence microscopy of high-density samplesHigh-density samples of fluorescent quantum dots (QDs) were imaged using an apertureless near-field optical microscopy technique. QD fluorescence was modulated by oscillating a silicon atomic force microscope tip above an illuminated sample and a lock-in amplifier was used to suppress background fr...2006
321 Vardeny, Zeev ValentineExperimental determination of the charge/neutral branching ratio η in the photoexcitation of ∏-conjugated polymers by broadband ultrafast spectroscopyWe demonstrate a long-sought reliable method for determining the important branching ratio η between photogenerated charged polarons and neutral excitons in ∏-conjugated polymer films and solutions, using femtosecond transient photomodulation spectroscopy with broad spectral range from 0.14 to ...pi-conjugated polymers; Charge/neutral branching ratio; Photoexcitation; nu value; Broadband ultrafast spectroscopy2007-02
322 Ailion, David Charles79Br nuclear-quadrupole-resonance lineshape and Raman-induced spin-lattice relaxation in the incommensurate phase of β- ThBr4We performed 7 9Br nuclear-quadrupole-resonance (NQR) line-shape and spin-lattice relaxation time measurements in the incommensurate (D system j8-ThBr4 over the temperature range 293-2.5 K. In addition, we extended the theory of the effects of Raman processes on amplitudon and phason spin-lattice re...Spin-lattice; NQR; Raman process; Line shape; Phason gap; Incommensurate systems1989
323 Mattis, Daniel C.Thermal conductivity and thermodynamics of phonons for an exactly soluble model of disorderWe calculate the exact thermal conductivity and the heat capacity of an insulator for which the lattice dynamics are given by a phonon gas in the presence of frozen-in disorder, in the special case of the "backward-scattering'' model of impurity scattering.Thermal conductivity; Heat capacity; Insulators; Defects; Phonon gas; Backward-scattering model1992-10
324 Williams, Clayton C.Single electron tunneling to insulator surfaces measured by frequency detection electrostatic force microscopySingle-electron tunneling events between a metal probe and an insulator surface are measured by frequency detection electrostatic force microscopy. Single-electron tunneling events typically cause 1-10 Hz shifts in the 300 kHz resonance frequency of the oscillating force probe. The frequency shift...Electrons; Tunneling events; Electrostatic force microscopy2004
325 Mattis, Daniel C.Long-ranged magnetic polarization effectsTwo years ago a group1 at Bell Telephone Laboratories discovered an exceedingly long-ranged magnetic interaction among rare earth (RE) atoms dissolved in palladium. It is the purpose of the present note to suggest a theory for this phenomenon, which, it will be recalled, could not be explained by t...Indirect exchange theory1964-05
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