UScholar Works
 
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CreatorTitleDescriptionSubjectDate
76 Symko, Orest GeorgeCalibration of SQUID magnetometer for dilute alloy studiesA SQUID magnetometer used in the study of dilute magnetic alloys or other weak magnetic systems can be calibrated by using the nuclear paramagnetism of aluminum metal. This material is useful as a calibration standard since magnetic impurities such as Fe and Mn form no local moment. This calibration...SQUID magnetometer1979
77 Gondolo, PaoloCan WIMP spin dependent couplings explain DAMA data, in light of null results from other experiments?We examine whether the annual modulation found by the DAMA dark matter experiment can be explained by Weakly Interacting Massive Particles (WIMPs), in light of new null results from other experiments. CDMS II has already ruled out most WIMP-nucleus spin-independent couplings as an explanation for DA...WIMP; Weakly interacting massive particles; DAMA; CDMS II; Parameter space2004-12
78 Dawson, KyleCCD testing and characterization for dark energy surveyA description of the plans and infrastructure developed for CCD testing and characterization for the DES focal plane detectors is presented. Examples of the results obtained are shown and discussed in the context of the device requirements for the survey instrument.DES2006
79 Symko, Orest GeorgeChaos in long Josephson junctions without external rf driving forceSimulations of long Josephson junctions in an external magnetic field show a variety of chaotic behaviors. They consist of period-doubling bifurcation, intermittency between and within Fiske steps, and quasiperiodic motion at Fiske steps. A physical explanation for the chaotic behavior is presented....Fiske steps; Chaos; Chaotic behaviors1990-09
80 Symko, Orest GeorgeCharacteristics of YBaCuO magnetic shieldsMagnetic shielding properties of YBaCuO tubes have been studied at temperatures of 77 K and 4 K. Shielding effectiveness was determined by measuring the magnetic field inside the tube in the presence of external magnetic fields. A high degree of shielding was achieved up to a critical external fie...YBaCuO magnetic shields; SQUID1991-03
81 Wu, Yong-ShiCharacterization of one-dimensional Luttinger liquids in terms of fractional exclusion statisticsWe develop a bosonization approach to study the low temperature properties of one-dimensional gas of particles obeying fractional exclusion statistics (FES). It is shown that such ideal gas reproduces the low-energy excitations and asymptotic exponents of a one-component Luttinger liquid (with no in...2001-06
82 Stringfellow, Gerald B.;Inglefield, Colin E.;Taylor, P. CraigCharacterization of unicompositional GaInP2 ordering heterostructures grown by variation of V/III ratioPhotoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies are employed to investigate single heterostructures based on two GaInP2 layers that have the same composition but different degrees of order on the cation sublattice. Four sample configurations are studied: two complemen...Heterostructures; Growth parameters; Growth temperature1997
83 Mishchenko, EugeneCharge response function and a novel plasmon mode in graphenePolarizability of noninteracting 2D Dirac electrons has a 1 1 / √qv-ω singularity at the boundary of electron-hole excitations. The screening of this singularity by long-range electron-electron interactions is usually treated within the random phase approximation. The latter is exact only in the ...Excitons; Random phase approximation2008-04
84 DeTar, CarletonCharmed-meson decay constants in three-flavor lattice QCDWe present the first lattice QCD calculation with realistic sea quark content of the D+-meson decay constant fD+. We use the MILC Collaboration's publicly available ensembles of lattice gauge fields, which have a quark sea with two flavors (up and down) much lighter than a third (strange). We obtain...Flavor physics; Charmed meson; Staggered fermions2005-09
85 Wu, Yong-ShiChiral bosonization and local Lorentz-invariant actions for chiral bosonsWe formulate a geometrical theory of self-dual scalar fields in two dimensions with a local Lorentz-invariant action. Path-integral quantization is used to derive chiral bosonization by demonstrating equivalence of correlation functions of currents and energy-momentum tensors in our theory with thos...Bosonization; String theory; Weyl fermions1988-06
86 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
87 Vardeny, Zeev Valentine; Ehrenfreund, Eitan A.Classification of disorder and extrinsic order in polymers by resonant Raman scatteringResonant Raman scattering is used to quantify the effect of disorder and extrinsic order on Peierls systems such as (CH)X . We introduce "X plots" in which the phonon and gap distribution are related and characterize the system by the functional dependence of the gap 2 A on the coupling X. For c/s-r...Peierls systems1985-01
88 Gondolo, PaoloClumpy neutralino dark matterWe investigate the possibility to detect neutralino dark matter in a scenario in which the galactic dark halo is clumpy. We find that under customary assumptions on various astrophysical parameters, the antiproton and continuum γ-ray signals from neutralino annihilation in the halo put the strong...Neutralinos; Clumpiness1999-01
89 Vardeny, Zeev ValentineCoherent phonon generation and detection by picosecond light pulsesUsing the picosecond pump and probe technique we have detected oscillations of photoinduced transmission and reflection in thin films of α-As2Te3 and cis-polyacetylene. These oscillations are due to the generation and propagation of coherent acoustic phonons in the film. We discuss the generation ...a-As2Te3; Cis-polyacetylene; Pump and probe technique1984-09
90 Vardeny, Zeev Valentine; Raikh, Mikhail E.Coherent random lasing: trapping of light by the disorderRecent discovery of the coherent lasing from various disordered materials adds a new dimension to the conventional physics of light propagation in multiply scattering media. It suggests that in the situation, when the propagation of light is diffusive on average, the coherent feedback can be provid...Coherent random lasing; Coherent lasing; Disorder; Disordered materials; Random lasers; Random resonators; Power Fourier transform; Light propagation2004
91 Vardeny, Zeev ValentineCoherent umklapp scattering of light from disordered photonic crystalsA theoretical study of the coherent light scattering from disordered photonic crystals is presented. In addition to the conventional enhancement of the reflected light intensity into the backscattering direction, the so-called coherent backscattering (CBS), the periodic modulation of the dielectri...Coherent umklapp scattering; Disordered photonic crystals; Coherent backscattering; Bragg2001-05
92 Ailion, David CharlesCommensurability and defect-induced phason gaps in incommensurate systemsThe phason energy gap has been observed to increase on going from the incommensurate to higher-order commensurate phases in the "devil's staircase" compound [N(CH3)4]2ZnCl4. The gap was determined via the phason-induced 1 4N spin-lattice relaxation contribution, which was obtained from the variati...Phasons; Commensurate; Incommensurate; Lattices; Modulation1985
93 Vardeny, Zeev Valentine; Ehrenfreund, Eitan A.Comment on "Frequency response and origin of the spin-½ photoluminescence-detected magnetic resonance in a ∏-conjugated polymerIn a recent paper, Segal et al. [Phys. Rev. B 71, 245201 (2005)] advanced a new explanation for the dynamics of spin-1/2 photoluminescence-detected magnetic resonance (PLDMR) in films of a rr-conjugated polymer, namely, a soluble derivative of poly(phenylene-vinylene) (MEH-PPV), using a model [dubbe...Photoluminescence-detected magnetic resonance; PLDMR; pi-conjugated polymers; Poly(phenylene-vinylene); MEH-PPV2007-06
94 Mattis, Daniel C.Comment on "Ground-state properties of a spin-1 antiferromagnetic chainBotet and Jullien [Phys. Rev. B 27, 613 (1983)] and Botet, Jullien, and Kolb [Phys. Rev. B 28, 3914 (1983)] performed a finite-size scaling analysis of the spin-1 antiferromagnetic Heisenberg-Ising chain. Their work was criticized by Bonner and Mtiller [Phys. Rev. B 29, 5216 (1984)] on the grounds...Antiferromagnets; Ground-state; Ising chain; Energy gap1985-04
95 Vardeny, Zeev ValentineComment on "Large optical nonlinearity of semiconducting single-walled carbon nanotubes under resonant excitations"In a recent Letter Maeda et al. studied the optical nonlinearities of single-walled carbon nanotubes (SWNT) films using both ??Z-scan?? and ??pump and probe?? (PP) techniques with ~100 fs time resolution [1]. They found that SWNTs have a large resonant third-order nonlinear optical susceptibili...SWNT; Coherent artifact2006
96 Vardeny, Zeev Valentine; Ehrenfreund, Eitan A.Comment on "Yield of singlet excitons in organic light-emitting devices: a double modulation photoluminescence-detected magnetic resonance study"In a recent Letter [1] Lee et al. studied the spin 1/2 photoluminescence-detected magnetic resonance (PLDMR) of a soluble derivative of poly-phenylene vinylene [MEH-PPV] using a double modulation scheme, where both the laser excitation intensity and the microwave power were modulated at ?ex and ?...Singlet excitons; PLDMR; Poly-phenylene vinylene; MEH-PPV; Quenching; Spin dependent recombination; OLED2006
97 Saam, BrianComment on pressure dependence of wall relaxation in polarized 3He gaseous cellsZheng et al. [Zheng, Gao, Ye, and Zhang, Phys. Rev. A 83, 061401(R) (2011)] have measured a strong linear pressure dependence of the nuclear relaxation rate of 3He in glass cells typically used to generate and/or store polarized 3He at room and cryogenic temperatures. Their interpretation is that th...2012-01-01
98 Saam, BrianComment on: New limit on lorentz-invariance- and CPT-violating neutron spin interactions using a free-spin-precession 3He- 129Xe comagnetometerIn Ref. [1], the authors use a classical result for the magnetic field created by a uniform magnetization to analyze the effects of magnetic interactions between 3He and 129Xe nuclear spins. We point out that the classical result is not applicable for interaction between nuclear spins: the actual in...2014-01-01
99 Sokolsky, PierreComparison of air fluorescence and ionization measurements of E.M. shower depth profiles: test of a UHECR detector techniqueMeasurements are reported on the fluorescence of air as a function of depth in electromagnetic showers initiated by bunches of 28.5 GeV electrons. The light yield is compared with the expected and observed depth profiles of ionization in the showers. It validates the use of atmospheric fluorescence...Air fluorescence; Electromagnetic shower; Ultra-high energy cosmic rays; Ionization2006-02
100 Gondolo, PaoloCompatibility of DAMA dark matter detection with other searchesWe present two examples of velocity distributions for light dark matter particles that reconcile the annual modulation signal observed by DAMA with all other negative results from dark matter searches. They are: (1) a conventional Maxwellian distribution for particle masses around 5 to 9 GeV; (2) ...DAMA; CDMS; Neutralinos; WIMP; Weakly interacting massive particles; Halo models; Dark matter stream2005-06
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