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CreatorTitleDescriptionSubjectDate
1 Mattis, Daniel C.Phonon model of vacancy-interstitial pair formation in solidsBonds between neighboring atoms in a solid are imperfect harmonic oscillators. Through consideration of the nonlinearities, it is shown that vacancy-interstitial defect pairs can be described in terms of phonon dynamical variables. The effective spring constants are determined by self-consistency...Harmonic; Potential; Homogeneous1984
2 Gondolo, Paolo; Springer, Robert WayneSite characteristic of Southern Utah sites for astronomical observatoriesThe University of Utah has recently begun construction of a new 0.8m optical/IR robotic telescope to be operated as a regional astronomy resource in the Intermountain West. The new Southern Utah Observatory (SUO) will require a high altitude (>3000 m) site with excellent atmospheric seeing, favorab...2008
3 Williams, Clayton C.Single electron tunneling detected by electrostatic forceSingle electron tunneling events between a specially fabricated scanning probe and a conducting surface are demonstrated. The probe is an oxidized silicon atomic force microscope tip with an electrically isolated metallic dot at its apex. A voltage applied to the silicon tip produces an electrostat...Single electron; Tunneling events; Scanning tunneling microscope; Electrostatic modeling2001
4 Williams, Clayton C.Mapping of mobile charges on insulator surfaces with the electrostatic force microscopeMigration of surface ions in lateral fields on insulator surfaces may modify the electrical characteristics of underlying semiconductor structures causing device instabilities. A high sensitivity electrostatic force microscope is used to image the movement and spatial distribution of surface ions on...Insulator surfaces; Surface ions; Electrostatic force microscope1993
5 Williams, Clayton C.Shear force microscopy with capacitance detection for near-field scanning optical microscopyShear force microscopy is very useful for distance regulation in near-field scanning optical microscopy (NSOM). However, the optical method used to detect the shear force can cause problems when imaging photosensitive materials, i.e., the shear force detection beam can optically pump the sample. We ...Shear force microscopy; Atom force microscope; AFM; Capacitance sensing1995
6 Dawson, KyleSubaru FOCAS spectroscopic observations of high-redshift supernovaeWe present spectra of high-redshift supernovae (SNe) that were taken with the Subaru low-resolution optical spectrograph, FOCAS. These SNe were found in SN surveys with Suprime-Cam on Subaru, the CFH12k camera on the Canada-France-Hawaii Telescope, and the Advanced Camera for Surveys on the Hubble S...2010-01-01
7 Mattis, Daniel C.Theory of glass dynamics: the low-lying modes of anharmonic materialsWe study the lowest-lying excited states of arbitrary anharmonic solids (crystalline, glassy, or amorphous). Defining the harmonic ("skeleton") lattice underlying any such anharmonic medium, we find that its spectrum of elementary excitations provides a rigorous upper bound to that of the anharmonic...Spectrum; Arbitrary; Lattices1987
8 Williams, Clayton C.Modeling and experimental investigation of cantilever dynamics in force detected single electron tunnelingThe dynamic response of a voltage biased oscillating cantilever probe is investigated through experimental and theoretical analysis as it approaches a dielectric surface. When the tip reaches the appropriate gap single electron tunneling events are detected between the metallic tip and the surface. ...Oscillating cantilever probe; Electron tunneling2004
9 Gondolo, PaoloEffect of dark matter on the first stars: a new phase of stellar evolutionDark matter (DM) in protostellar halos can dramatically alter the current theoretical framework for the formation of the first stars. Heat from supersymmetric DM annihilation can overwhelm any cooling mechanism, consequently impeding the star formation process and possibly leading to a new stellar ...Dark stars2008
10 Mattis, Daniel C.Electron-phonon interaction in two dimensions: the case for strong coupling in high-Tc superconductorsA particular model interaction between electrons and acoustic phonons is found to cause electrons to become weakly "self-trapped" for an arbitrary filling factor in d=2, but not in d=1 nor, for different reasons, in d>3. To the extent that electron kinetic energy is reduced in d=2, the electronic in...Strong coupling1987-09
11 Williams, Clayton C.Instability induced tunneling and repeatable charge injection to SiO2 surfaces by electrostatic force microscopyThe dynamic response and stability of a voltage biased oscillating cantilever in the proximity of an insulating sample surface is investigated. As the tip approaches the sample surface, the cantilever can jump between two different oscillation modes. The jump is detected as an abrupt increase in t...Electrostatic force microscopy; EFM; Dielectric films2004
12 Williams, Clayton C.Single electron tunneling to insulator surfaces detected by electrostatic forceThe detection of single-electron tunneling events between a metallic scanning probe tip and an insulating surface is demonstrated by an electrostatic force method. When a voltage-biased oscillating atomic force microscopy tip is placed within tunneling range of the surface of an insulator, single...Single electron; Tunneling events; Scanning tunneling microscope2002
13 Vardeny, Zeev ValentineFabrication and properties of gallium metallic photonic crystalsGallium metallic photonic crystals with 100% filling factor have been fabricated via infiltration of liquid gallium into opals of 300-nm silica spheres using a novel high pressure-high temperature technique. The electrical resistance of the Ga-opal crystals was measured at temperatures from 10 to 2...2003-10
14 Wu, Yong-ShiWave function describing superfluidity in a perfect crystalWe propose a many-body wave function that exhibits both diagonal and off-diagonal long-range order. Incorporating short-range correlations due to interatomic repulsion, this wave function is shown to allow condensation of zero-point lattice vibrations and phase rigidity. In the presence of an exter...2005-07-01
15 Williams, Clayton C.; Stringfellow, Gerald B.Effect of substrate misorientation on ordering in Ga0.5In0.5POrdering produced in Gao.5Ino.5P epitaxial layers grown by OMVPE can be controlled by variations in the substrate misorientation as well as the growth temperature and the growth rate. The ordering produced at a growth temperature of 620°C and a relatively low growth rate of 0.5 /μm/hr is found to ...Ga0.5In0.5P; Epitaxial layers; Epitaxial growth; OMVPE1994
16 Gondolo, PaoloLight dark matter in leptophobic Z' modelsRecent experimental results in direct dark matter detection may be interpreted in terms of a dark matter particle of mass around 10 GeV=c2. We show that the required scenario can be realized with a new dark matter particle charged under an extra Abelian gauge boson Z0 that couples to quarks but not ...2012-01-01
17 Mattis, Daniel C.A contribution to the many-fermion problemIn this work we reexamine the many-fermion problem in arbitrary dimensions. It is shown that in two dimensions or higher, the Hamiltonian of interacting fermions can be separated into individual nonintersecting sectors labeled by the wave-vector q. Within each sector the Hamiltonian maps onto a gene...2012-01-01
18 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
19 Gondolo, PaoloDetectability of weakly interacting massive particles in the Sagittarius dwarf tidal streamTidal streams of the Sagittarius dwarf spheroidal galaxy (Sgr) may be showering dark matter onto the solar system and contributing ~(0:3-23)% of the local density of our galactic halo. If the Sagittarius galaxy contains dark matter in the form of weakly interacting massive particles (WIMPs), the ext...WIMP; Weakly interacting massive particles; Sagittarius dwarf galaxy; Recoil energy; Sgr stream2005-02
20 Vardeny, Zeev ValentineOptical and transport studies of single molecule tunnel junctions based on self-assembled monolayersWe have fabricated a variety of novel molecular tunnel junctions based on self-assembled-monolayers (SAM) of two-component solid-state mixtures of molecular wires (1,4 methane benzene-dithiol; Me-BDT with two thiol anchoring groups), and molecular insulator spacers (1-pentanethiol; PT with one thio...2005-09
21 Gondolo, PaoloAnnual modulation of dark matter in the presence of streamsIn addition to a smooth component of weakly interacting massive particle (WIMP) dark matter in galaxies, there may be streams of material; the effects of WIMP streams on direct detection experiments is examined in this paper. The contribution to the count rate due to the stream cuts off at some char...WIMP streams; Weakly interacting massive particles; Cutoff energy; Halo models; Sagittarius dwarf galaxy; Recoil energy; Sgr stream2006-08
22 Gondolo, PaoloPhase-space distribution of unbound dark matter near the sunWe resolve discrepancies in previous analyses of the flow of collisionless dark matter particles in the Sun's gravitational field. We determine the phase-space distribution of the flow both numerically, tracing particle trajectories back in time, and analytically, providing a simple correct relati...Phase-space distribution; Gravitational field; Velocity functions2006-10
23 Mattis, Daniel C.Few-body problem on a latticeThe author explores some of the inherent simplifications of "quantum lattice physics." He distinguishes between fermions and bosons and analyzes the n-body problem for each, with n = 1,2,3... typically a small number. With delta-function (zero-range) interactions, the three-body problem on a lattice...Quantum; Electrons; Spin1986
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