Results for "M. S. Avirett-Mackenzie"

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The evolving X-ray spectrum of active galactic nuclei: evidence for an increasing reflection fraction with redshiftApr 12 2019The cosmic X-ray background (XRB) spectrum and active galaxy number counts encode essential information about the spectral evolution of active galactic nuclei (AGNs) and have been successfully modeled by XRB synthesis models for many years. Recent measurements ... More
Hydrodynamic Torques in Circumbinary Accretion DisksFeb 28 2019Gaseous disks have been proposed as a mechanism for facilitating mergers of binary black holes. We explore circumbinary disk systems to determine the evolution of the central binary. To do so, we perform 3D, hydrodynamic, locally isothermal simulations ... More
The anti-B --> D* lepton anti-neutrino form factor at zero recoil and the determination of V(cb)Oct 24 2001We summarize our lattice QCD study of the form factor at zero recoil in the decay anti-B --> D* lepton anti-neutrino. After careful consideration of all sources of systematic uncertainty, we find, h_A1(1) = 0.913(+0.024-0.017)(+0.017-0.030), where the ... More
Q-balls in Maxwell-Chern-Simons theoryApr 05 2006Jul 18 2006We examine the energetics of Q-balls in Maxwell-Chern-Simons theory in two space dimensions. Whereas gauged Q-balls are unallowed in this dimension in the absence of a Chern-Simons term due to a divergent electromagnetic energy, the addition of a Chern-Simons ... More
Solitons in SO(5) SuperconductivityMay 19 1999A model unifying superconductivity and antiferromagnetism using an underlying approximate SO(5) symmetry has injected energy into the field of high-temperature superconductivity. This model might lead to a variety of interesting solitons. In this paper, ... More
Maxwell-Chern-Simons Q-ballsJun 27 2006We examine the energetics of $Q$-balls in Maxwell-Chern-Simons theory in two space dimensions. Whereas gauged $Q$-balls are unallowed in this dimension in the absence of a Chern-Simons term due to a divergent electromagnetic energy, the addition of a ... More
B and D semileptonic decays to light mesonsOct 04 1999We present an update of our calculation of the form factors and partial widths of semileptonic heavy-to-light meson decays, in the quenched approximation. Our complete data set has now been analysed and our results include chiral extrapolations and a ... More
B and D Meson Decay Constants in Lattice QCDNov 22 1997We have calculated the decay constants of B and $D$ mesons with lattice QCD. We use an $O(a)$ improved action that takes light quark actions as a starting point, tuned so that it can be directly applied at the physical masses of the $b$ and $c$ quarks. ... More
F(1) for B -> D^*lνfrom Lattice QCDJul 09 2002Short description of our calculation of the form factor needed to determine CKM element |V_{cb}| from the exclusive decay B -> D^*l\nu. For full details, see hep-ph/0110253. Also, here we recommend distribution for CKM fits.
The Semileptonic Decays $B\toπlν$ and $D\toπlν$ from Lattice QCDJan 02 2001We present a lattice QCD calculation of the form factors and differential decay rates for semileptonic decays of the heavy-light mesons $B$ and $D$ to the final state $\pi l\nu$. The results are obtained with three methodological improvements over previous ... More
The properties of Brightest Cluster Galaxies in the SDSS DR6 adaptive matched filter cluster catalogueNov 12 2010We study the properties of Brightest Cluster Galaxies (BCGs) drawn from a catalogue of more than 69000 clusters in the SDSS DR6 based on the adaptive matched filter technique (AMF, Szabo et al., 2010). Our sample consists of more than 14300 galaxies in ... More
Lattice calculation of the zero-recoil form factor of anti-B --> D* lepton anti-neutrino: toward a model independent determination of |V(cb)|Oct 18 2001We develop a new method in lattice QCD to calculate the form factor F(1) at zero recoil. This is the main theoretical ingredient needed to determine |V(cb)| from the exclusive decay anti-B --> D* lepton anti-neutrino. We introduce three ratios, in which ... More
A Relativistic $O(a^2)$ Improved Action for Heavy QuarksSep 23 2002We extend the Fermilab formalism for heavy quarks to develop an $O(a^2)$ improved relativistic action. We discuss our construction of the action, including the identification of redundant operators and the calculation of the improvement coefficients.
A More Improved Lattice Action for Heavy QuarksOct 06 2003We extend the Fermilab formalism for heavy quarks to develop a more improved action. We give results of matching calculations of the improvement couplings at tree level. Finally, we estimate the discretization errors associated with the new action.
Magnetic properties of SO(5) superconductivityFeb 22 2002The distinction between type I and type II superconductivity is re-examined in the context of the SO(5) model recently put forth by Zhang. Whereas in conventional superconductivity only one parameter (the Ginzburg-Landau parameter $\kappa$) characterizes ... More
The B -> D* l nu Form Factor at Zero RecoilOct 13 1999We describe a model independent lattice QCD method for determining the deviation from unity for h_{A1}(1), the B -> D* l nu form factor at zero recoil. We extend the double ratio method previously used to determine the B -> D l nu form factor. The bulk ... More
B -> pi l nu at three lattice spacingsOct 20 1998The increasing accuracy of experimental results for the exclusive, semileptonic decay B -> pi l nu requires a similarly accurate calculation of the hadronic matrix elements, to determine |Vub|. We present preliminary results for the form factors of the ... More
Planar Superconductivity via Kosterlitz-Thouless mechanismDec 11 1995The phase structure of a $(2+1)$ - dimensional model of relativistic fermions with a four fermi interaction is analyzed in the strong coupling regime using the large $N$ perturbation theory. It is shown that, this model exhibits a low temperature superconducting ... More
Progress in QCD Using Lattice Gauge TheoryMar 25 1993Review of results from lattice QCD of relevance to standard-model phenomenology, to appear in Annual Review of Nuclear and Particle Science. KEY WORDS: hadron masses, quark mixing (CKM) matrix, weak matrix elements, strong coupling constant.
Generalizations of generating functions for hypergeometric orthogonal polynomials with definite integralsFeb 11 2013We generalize generating functions for hypergeometric orthogonal polynomials, namely Jacobi, Gegenbauer, Laguerre, and Wilson polynomials. These generalizations of generating functions are accomplished through series rearrangement using connection relations ... More
Estimated Errors in |Vcd|/|Vcs| from Semileptonic D DecaysOct 20 1998We estimate statistical and systematic errors in the extraction of the CKM ratio |Vcd|/|Vcs| from exclusive D-meson semileptonic decays using lattice QCD and anticipated new experimental results.
B -> D l nu form factors and the determination of |Vcb|Oct 27 1998The zero recoil limit of the B -> D l nu form factors is calculated on the lattice, which provides a model-independent determination of |Vcb|. Considering a ratio of form factors, in which the bulk of statistical and systematic errors cancel, we obtain ... More
Superconductivity in $2+1$ dimensions via Kosterlitz-Thouless Mechanism: Large-N and Finite-Temperature AnalysesSep 08 1993We analyse a $2+1$ dimensional model with charged, relativistic fermions interacting through a four-Fermi term. Taking advantage of its large-$N$ renormalizability, the various phases of this model are studied at finite temperature and beyond the leading ... More
Integrating Newer Technology Software Systems into the SLAC Legacy Control System - Two Case Histories and New CMLOG DevelopmentsNov 27 2001It has been the goal of SLAC Controls Software to offload processing from the aging Alpha/VMS based control system onto machines that are more widely accepted and used. An additional goal has been to provide more modern software tools to our user community. ... More
On the Coleman-Hill TheoremAug 16 1994The Coleman-Hill theorem prohibits the appearance of radiative corrections to the topological mass (more precisely, to the parity-odd part of the vacuum polarization tensor at zero momentum) in a wide class of abelian gauge theories in 2+1 dimensions. ... More
Lattice QCD calculation of $\bar{B}\to Dl\barν$ decay form factors at zero recoilJun 15 1999Oct 27 1999A lattice QCD calculation of the $\bar{B}\to Dl\bar{\nu}$ decay form factors is presented. We obtain the value of the form factor $h_+(w)$ at the zero-recoil limit $w=1$ with high precision by considering a ratio of correlation functions in which the ... More
Evolution of black hole and galaxy growth in a semi-numerical galaxy formation modelJul 01 2019We present a simple semi-numerical model designed to explore black hole growth and galaxy evolution. This method builds on a previous model for black hole accretion that uses a semi-numerical galaxy formation model and universal Eddington ratio distribution ... More
Optimizing adiabaticity in quantum mechanicsSep 12 2011A condition on the Hamiltonian of a time-dependent quantum mechanical system is derived which, if satisfied, implies optimal adiabaticity (defined below). The condition is expressed in terms of the Hamiltonian and in terms of the evolution operator related ... More
From Q-walls to Q-ballsApr 09 2001We study $Q$-ball type solitons in arbitrary spatial dimensions in the setting recently described by Kusenko, where the scalar field potential has a flat direction which rises much slower than $\phi^2$. We find that the general formula for energy as a ... More
Onium Masses with Three Flavors of Dynamical QuarksOct 12 2005We have greatly extended an earlier calculation of the charmonium spectrum on three flavor dynamical quark ensembles by using more recent ensembles generated by the MILC collaboration. The heavy quarks are treated using the Fermilab formulation. The charmonium ... More
Observation of Two-dimensional Spin Fluctuations in the Bilayer Ruthenate Sr3Ru2O7 by Inelastic Neutron ScatteringJan 30 2002We report the first observation of two-dimensional incommensurate magnetic fluctuations in the layered metallic perovskite Sr3Ru2O7. The wavevectors where the magnetic fluctuations are strongest are different from those observed in the superconducting ... More
The Structure of Rh$_8^+$ in the Gas PhaseSep 30 2009The geometric structure of the Rh$_8^+$ cation is investigated using a combination of far-infrared multiple photon dissociation spectroscopy and density functional theory (DFT) calculations. The energetic ordering of the different structural motifs is ... More
Vortex lattice stability in the SO(5) modelJun 08 2001We study the energetics of superconducting vortices in the SO(5) model for high-$T_c$ materials proposed by Zhang. We show that for a wide range of parameters normally corresponding to type II superconductivity, the free energy per unit flux $\FF(m)$ ... More
Heavy d-Electron Quasiparticle Interference and Real-space Electronic Structure of Sr3Ru2O7Nov 15 2009Nov 17 2009The intriguing idea that strongly interacting electrons can generate spatially inhomogeneous electronic liquid crystalline phases is over a decade old, but these systems still represent an unexplored frontier of condensed matter physics. One reason is ... More
Thermal conductivity in the vicinity of the quantum critical endpoint in Sr3Ru2O7Feb 20 2006Sep 05 2006Thermal conductivity of Sr3Ru2O7 was measured down to 40 mK and at magnetic fields through the quantum critical endpoint at H_c = 7.85 T. A peak in the electrical resistivity as a function of field was mimicked by the thermal resistivity. In the limit ... More
High precision heat capacity measurements on Sr2RuO4 under uniaxial pressureJun 18 2019The heat capacity is one of the most fundamental properties that can be studied in any material, vital in the search for exotic phase transitions. Given the rapid developments in tuning the physical properties of solids by the application of external ... More
Equivalence of the grand canonical partition functions of particles with different statisticsAug 27 1997It is shown that the grand partition function of an ideal Bose system with single particle spectrum $\epsilon_i = (2n+k+3/2)\hbar\omega$ is identical to that of a system of particles with single particle energy $\epsilon_i =(n+1/2)\hbar\omega$ and obeying ... More
Perfect separation of intraband and interband excitations in PdCoO$_2$Nov 02 2018May 06 2019The temperature dependence of the optical properties of the delafossite PdCoO$_2$ has been measured in the a-b planes over a wide frequency range. The optical conductivity due to the free-carrier (intraband) response falls well below the interband transitions, ... More
Update on onium masses with three flavors of dynamical quarksSep 30 2009We update results presented at Lattice 2005 on charmonium masses. New ensembles of gauge configurations with 2+1 flavors of improved staggered quarks have been analyzed. Statistics have been increased for other ensembles. New results are also available ... More
Fermi surface and quasiparticle excitations of Sr$_{2}$RhO$_{4}$Apr 18 2006The electronic structure of the layered 4$d$ transition metal oxide Sr$_{2}$RhO$_{4}$ is investigated by angle resolved photoemission. We find well-defined quasiparticle excitations with a highly anisotropic dispersion, suggesting a quasi-two-dimensional ... More
The Light Quark Masses from Lattice Gauge TheoryOct 02 1996We investigate the masses of the light quarks with lattice QCD. We show that most of the large dependence on the lattice spacing, a, observed in previous determinations using Wilson fermions is removed with the use of an O(a) corrected action. In the ... More
Quarkonium mass splittings in three-flavor lattice QCDDec 14 2009We report on calculations of the charmonium and bottomonium spectrum in lattice QCD. We use ensembles of gauge fields with three flavors of sea quarks, simulated with the asqtad improved action for staggered fermions. For the heavy quarks we employ the ... More
Quarkonium mass splittings with Fermilab heavy quarks and 2+1 flavors of improved staggered sea quarksNov 02 2009We present results from an ongoing lattice study of the lowest lying charmonium and bottomonium level splittings using the Fermilab heavy quark formalism. Our objective is to test the performance of this action on MILC-collaboration ensembles of (2+1) ... More
Structure of Titan's evaporitesDec 22 2015Numerous geological features that could be evaporitic in origin have been identified on the surface of Titan. Although they seem to be water-ice poor, their main properties -chemical composition, thickness, stratification- are essentially unknown. In ... More
Phase transitions in a gas of anyonsJul 19 2010We continue our numerical Monte Carlo simulation of a gas of closed loops on a 3 dimensional lattice, however now in the presence of a topological term added to the action corresponding to the total linking number between the loops. We compute the linking ... More
QCD on Coarse LatticesDec 06 1994We show that the perturbatively-improved gluon action for QCD, once it is tadpole-improved, gives accurate results even with lattice spacings as large as 0.4~fm. {\em No\/} tuning of the couplings is required. Using this action and lattice spacing, we ... More
Path integration and perturbation theory with complex Euclidean actionsFeb 04 2008Apr 04 2008The Euclidean path integral quite often involves an action that is not completely real {\it i.e.} a complex action. This occurs when the Minkowski action contains $t$-odd CP-violating terms. Analytic continuation to Euclidean time yields an imaginary ... More
Problems With Complex ActionsSep 21 2006We consider Euclidean functional integrals involving actions which are not exclusively real. This situation arises, for example, when there are $t$-odd terms in the the Minkowski action. Writing the action in terms of only real fields (which is always ... More
Spectroscopy of B_s and D_s MesonsNov 25 1997We study Bs and Ds spectroscopy in quenched lattice QCD using the Fermilab approach to heavy quarks. We obtain results at four lattice spacings, $a$, using $O(a)$-improved Wilson quarks. We compare and contrast the various methods for heavy quarks on ... More
Induced $B\wedge F$ term and photon mass generation in 3+1 dimensionsNov 12 1993Analysing a 3+1 dimensional model with four-Fermi interactions, we show that topological $\BF$ terms (both abelian and non-abelian) can be induced radiatively by massive fermions at the one-loop level. It is further pointed out that a mechanism of photon ... More
Massive Fermions in Lattice Gauge TheoryApr 04 1996This paper presents a formulation of lattice fermions applicable to all quark masses, large and small. We incorporate interactions from previous light-fermion and heavy-fermion methods, and thus ensure a smooth connection to these limiting cases. The ... More
Light Quark Masses with an O(a)-Improved ActionSep 05 1996Nov 22 1996We present the recent Fermilab calculations of the masses of the light quarks, using tadpole-improved Sheikholeslami-Wohlert (SW) quarks. Various sources of systematic errors are studied. Our final result for the average light quark mass in the quenched ... More
Tunneling decay of false domain walls: the silence of the lambsJun 18 2015We study the decay of "false" domain walls, which are metastable states of the quantum theory where the true vacuum is trapped inside the wall, with the false vacuum outside. We consider a theory with two scalar fields, a shepherd field and a field of ... More
Cosmic Ferromagnetism of MagninosJan 04 2019Jan 17 2019We study the physical conditions for the occurrence of ferromagnetic instability in a neutral plasma of fermions. We consider a system of two species $M$ and $Y$ which are oppositely charged under a local $U(1)_{X}$, with $M$ much lighter than $Y$. The ... More
Simulating Turbulence-aided Neutrino-driven Core-collapse Supernova Explosions in One DimensionFeb 04 2019The core-collapse supernova (CCSN) mechanism is fundamentally three-dimensional with instabilities, convection, and turbulence playing crucial roles in aiding neutrino-driven explosions. Simulations of CCNSe including accurate treatments of neutrino transport ... More
A Tale of Two Narrow-Line Regions: Ionization, Kinematics, and Spectral Energy Distributions for a Local Pair of Merging Obscured Active GalaxiesMar 21 2016We explore the gas ionization and kinematics, as well as the optical--IR spectral energy distributions for UGC 11185, a nearby pair of merging galaxies hosting obscured active galactic nuclei (AGNs), also known as SDSS J181611.72+423941.6 and J181609.37+423923.0 ... More
Phase transitions in a 3 dimensional lattice loop gasOct 17 2007Jul 20 2010We investigate, via Monte Carlo simulations, the phase structure of a system of closed, nonintersecting but otherwise non-interacting, loops in 3 Euclidean dimensions. The loops correspond to closed trajectories of massive particles and we find a phase ... More
Interaction between vortices in models with two order parametersJan 23 2003Jun 01 2003The interaction energy and force between widely separated strings is analyzed in a field theory having applications to superconducting cosmic strings, the SO(5) model of high-temperature superconductivity, and solitons in nonlinear optics. The field theory ... More
A Microscopic Derivation of the SO(5)-Symmetric Landau-Ginzburg PotentialJul 28 1997Jul 29 1997We construct a microscopic model of electron interactions which gives rise to both superconductivity and antiferromagnetism, and which admits an approximate SO(5) symmetry that relates these two phases. The symmetry can be exact, or it may exist only ... More
Metamagnetism and critical fluctuations in high quality single crystals of the bilayer ruthenate Sr3Ru2O7Aug 01 2000We report the results of low temperature transport, specific heat and magnetisation measurements on high quality single crystals of the bilayer perovskite Sr3Ru2O7, which is a close relative of the unconventional superconductor Sr2RuO4. Metamagnetism ... More
Vortex lattice structures and pairing symmetry in Sr2RuO4Jan 28 2000Recent experimental results indicate that superconductivity in Sr2RuO4 is described by the p-wave E_u representation of the D_{4h} point group. Results on the vortex lattice structures for this representation are presented. The theoretical results are ... More
Cascade of magnetic field induced Lifshitz transitions in the ferromagnetic Kondo lattice material YbNi4P2Dec 19 2016Oct 04 2017A ferromagnetic quantum critical point is thought not to exist in two and three-dimensional metallic systems yet is realized in the Kondo lattice compound YbNi4(P,As)2, possibly due to its one-dimensionality. It is crucial to investigate the dimensionality ... More
Quantum oscillations near the metamagnetic transition in Sr3Ru2O7Sep 07 2009Mar 01 2010We report detailed investigation of quantum oscillations in Sr3Ru2O7, observed inductively (the de Haas-van Alphen effect) and thermally (the magnetocaloric effect). Working at fields from 3 T to 18 T allowed us to straddle the metamagnetic transition ... More
EMU and ECB ConflictsJul 21 2018In dynamical framework the conflict between government and the central bank according to the exchange Rate of payment of fixed rates and fixed rates of fixed income (EMU) convergence criteria such that the public debt / GDP ratio The method consists of ... More
Quantum oscillations in the anomalous phase in Sr3Ru2O7Feb 23 2009Jan 11 2010We report measurements of quantum oscillations detected in the putative nematic phase of Sr3Ru2O7. Significant improvements in sample purity enabled the resolution of small amplitude dHvA oscillations between two first order metamagnetic transitions delimiting ... More
From symplectic groupoids to double structuresMar 15 2015These notes are an introduction to symplectic groupoids and the double structures associated with them. The treatment is intended to lie about midway between the original account of Coste, Dazord and Weinstein, which relied on effective use of the symplectic ... More
Is Faith The Enemy Of Science?Jul 23 2008In this article, inspired by Lawrence Krauss' plenary talk at the 2007 CAP congress, the relation between faith and science is examined.
Maximal Rashba-like spin splitting via kinetic energy-driven inversion symmetry breakingAug 13 2017Engineering and enhancing inversion symmetry breaking in solids is a major goal in condensed matter physics and materials science, as a route to advancing new physics and applications ranging from improved ferroelectrics for memory devices to materials ... More
Magnetic-field Induced Interconversion of Cooper Pairs and Density Wave States within Cuprate Composite OrderAug 03 2015Aug 17 2015Recent studies establish that the cuprate pseudogap phase is susceptible at low temperatures to forming not only a $d$-symmetry superconducting (SC) state, but also a $d$-symmetry form factor (dFF) density wave (DW) state. The concurrent emergence of ... More
Detection of a Cooper-Pair Density Wave in Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+x}$Nov 25 2015Jan 21 2016The quantum condensate of Cooper-pairs forming a superconductor was originally conceived to be translationally invariant. In theory, however, pairs can exist with finite momentum $Q$ and thereby generate states with spatially modulating Cooper-pair density. ... More
Magnetic-field Induced Interconversion of Cooper Pairs and Density Wave States within Cuprate Composite OrderAug 03 2015Jul 07 2018Recent studies establish that the cuprate pseudogap phase is susceptible at low temperatures to forming not only a $d$-symmetry superconducting (SC) state, but also a $d$-symmetry form factor (dFF) density wave (DW) state. The concurrent emergence of ... More
Strain Control of Fermiology and Many-Body Interactions in Two-Dimensional RuthenatesMay 18 2016Here we demonstrate how the Fermi surface topology and quantum many-body interactions can be manipulated via epitaxial strain in the spin-triplet superconductor Sr$_2$RuO$_4$ and its isoelectronic counterpart Ba$_2$RuO$_4$ using oxide molecular beam epitaxy ... More
Normal state $^{17}$O NMR studies of Sr$_{2}$RuO$_{4}$ under uniaxial stressOct 02 2018Jun 01 2019The effects of uniaxial compressive stress on the normal state $^{17}$O nuclear magnetic resonance properties of the unconventional superconductor Sr$_{2}$RuO$_{4}$ are reported. The paramagnetic shifts of both planar and apical oxygen sites show pronounced ... More
Path Integral Methods and ApplicationsApr 24 2000These lectures are intended as an introduction to the technique of path integrals and their applications in physics. The audience is mainly first-year graduate students, and it is assumed that the reader has a good foundation in quantum mechanics. No ... More
Remarks on gauge vortex scatteringMar 07 1995Apr 20 1995In the abelian Higgs model, among other situations, it has recently been realized that the head-on scattering of $n$ solitons distributed symmetrically around the point of scattering is by an angle $\pi/n$, independant of various details of the scattering. ... More
Sun Bin's LegacyApr 03 2014A common format for sports contests involves pairwise matches between two teams, with the #1 player of team A matched against the #1 player of team B, the #2 player of team A against the #2 player of team B, and so on. This paper addresses the following ... More
Pressure study of nematicity and quantum criticality in Sr$_3$Ru$_2$O$_7$ for an in-plane fieldAug 26 2013Jan 24 2014We study the relationship between the nematic phases of Sr$_3$Ru$_2$O$_7$ and quantum criticality. At ambient pressure, one nematic phase is associated with a metamagnetic quantum critical end point (QCEP) when the applied magnetic field is near the \textit{c}-axis. ... More
Full nonperturbative QCD simulations with 2+1 flavors of improved staggered quarksMar 23 2009Sep 12 2009Dramatic progress has been made over the last decade in the numerical study of quantum chromodynamics (QCD) through the use of improved formulations of QCD on the lattice (improved actions), the development of new algorithms and the rapid increase in ... More
Atomic-scale Electronic Structure of the Cuprate d-Symmetry Form Factor Density Wave StateJul 28 2015Extensive research into high temperature superconducting cuprates is now focused upon identifying the relationship between the classic 'pseudogap' phenomenon$^{1,2}$ and the more recently investigated density wave state$^{3-13}$. This state always exhibits ... More
Magnetic behaviour of SO(5) superconductorsJul 12 2002The distinction between type I and type II superconductivity is re-examined in the context of the SO(5) model recently put forth by Zhang. Whereas in conventional superconductivity only one parameter (the Ginzburg-Landau parameter $\kappa$) characterizes ... More
Normal state $^{17}$O NMR studies of Sr$_{2}$RuO$_{4}$ under uniaxial stressOct 02 2018The effects of uniaxial compressive stress on the normal state $^{17}% $O\ nuclear magnetic resonance properties of the unconventional superconductor Sr$_{2}$RuO$_{4}$ are reported. The paramagnetic shifts of both planar and apical oxygen sites show pronounced ... More
A reconstruction from small-angle neutron scattering measurements of the real space magnetic field distribution in the mixed state of Sr$_2$RuO$_4$Feb 08 2000We have measured the diffracted neutron scattering intensities from the square magnetic flux lattice in the perovskite superconductor Sr$_2$RuO$_4$, which is thought to exhibit p-wave pairing with a two-component order parameter. The relative intensities ... More
Quantum critical metamagnetism of Sr3Ru2O7 under hydrostatic pressureJan 06 2011Using ac susceptibility, we have determined the pressure dependence of the metamagnetic critical end point temperature T* for field applied in the ab-plane in the itinerant metamagnet Sr3Ru2O7. We find that T* falls monotonically to zero as pressure increases, ... More
Evidence from Tunneling Spectroscopy for a Quasi-One Dimensional Origin of Superconductivity in Sr2RuO4Aug 05 2013Nov 21 2013To establish the mechanism of unconventional superconductivity in Sr$_2$RUO$_4$, a prerequisite is direct information concerning the momentum-space structure of the energy gaps $\Delta_i(k)$, and in particular whether the pairing strength is stronger ... More
Itinerant ferromagnetism of the Pd-terminated polar surface of PdCoO$_2$Oct 15 2017We study the electronic structure of the Pd-terminated surface of the non-magnetic delafossite oxide metal PdCoO$_2$. Combining angle-resolved photoemission spectroscopy and density-functional theory, we show how an electronic reconstruction driven by ... More
Raman Spectral Indicators of Catalyst Decoupling for Transfer of CVD Grown 2D MaterialsMay 14 2018Through a combination of monitoring the Raman spectral characteristics of 2D materials grown on copper catalyst layers, and wafer scale automated detection of the fraction of transferred material, we reproducibly achieve transfers with over 97.5% monolayer ... More
Fermi surface and van Hove singularities in the itinerant metamagnet Sr3Ru2O7Mar 06 2008Jun 26 2008The low-energy electronic structure of the itinerant metamagnet Sr3Ru2O7 is investigated by angle resolved photoemission and density functional calculations. We find well-defined quasiparticle bands with resolution limited line widths and Fermi velocities ... More
Detailed Topography of the Fermi Surface of Sr2RuO4Sep 02 1999We apply a novel analysis of the field and angle dependence of the quantum-oscillatory amplitudes in the unconventional superconductor Sr2RuO4 to map its Fermi surface in unprecedented detail, and to obtain previously inaccessible information on the band ... More
Dissociation energies of AgRG (RG = Ar, Kr, Xe) and AgO molecules from velocity map imaging studiesSep 07 2015The near ultraviolet photodissociation dynamics of silver atom rare gas dimers have been studied by velocity map imaging. AgRG (RG = Ar, Kr, Xe) species generated by laser ablation are excited in the region of the C <- X continuum leading to direct, near ... More
Resistivity in the Vicinity of a Van Hove Singularity: Sr$_2$RuO$_4$ Under Uniaxial PressureSep 19 2017We report the results of a combined study of the normal state resistivity and superconducting transition temperature $T_c$ of the unconventional superconductor Sr$_2$RuO$_4$ under uniaxial pressure. There is strong evidence that as well as driving $T_c$ ... More
K -> pi l nu form factors with staggered quarksNov 08 2011We report on the status of the Fermilab-MILC calculation of the form factor f_+^{K pi}(0), needed to extract the CKM matrix element |V_{us}| from experimental data on K semileptonic decays. The HISQ formulation is used in the simulations for the valence ... More
Quantum criticality and the formation of a putative electronic liquid crystal in Sr3Ru2O7Jan 31 2012May 22 2012We present a brief review of the physical properties of Sr3Ru2O7, in which the approach to a magnetic-field-tuned quantum critical point is cut off by the formation of a novel phase with transport characteristics consistent with those of a nematic electronic ... More
Rigid-Band Shift of the Fermi Level in a Strongly Correlated Metal: Sr(2-y)La(y)RuO(4)Mar 13 2004We report a systematic study of electron doping of Sr2RuO4 by non-isovalent substitution of La^(3+) for Sr^(2+). Using a combination of de Haas-van Alphen oscillations, specific heat, and resistivity measurements, we show that electron doping leads to ... More
Diffusive and ballistic current spin-polarization in magnetron-sputtered L1o-ordered epitaxial FePtJul 19 2007We report on the structural, magnetic, and electron transport properties of a L1o-ordered epitaxial iron-platinum alloy layer fabricated by magnetron-sputtering on a MgO(001) substrate. The film studied displayed a long range chemical order parameter ... More
Lattice QCD on Small ComputersJul 07 1995Sep 18 1995We demonstrate that lattice QCD calculations can be made $10^3$--$10^6$ times faster by using very coarse lattices. To obtain accurate results, we replace the standard lattice actions by perturbatively-improved actions with tadpole-improved correction ... More
Visual Analysis and Demographics of Kepler Transit Timing VariationsMar 06 2019We visually analyzed the Transit Timing Variation (TTV) data of 5930 Kepler Objects of Interest (KOIs) homogeneously. Using data from Rowe et al. 2014 and Holczer et al. 2016, we investigated TTVs for KOIs in Kepler's Data Release 24 catalog. Using TTV ... More
Transport spin polarisation in SrRuO3 measured through Point Contact Andreev reflectionAug 02 2002Nov 05 2002We report a study in which Andreev reflection using a Nb point contact is used to measure the transport spin polarisation of the 4d itinerant ferromagnet SrRuO3. By performing the study in high quality thin films with residual resistivities less than ... More
The abelian and non-abelian Josephson effect and pseudo-goldstone bosonsOct 16 2005We formulate the Josephson effect in a field theoretic language which affords a straightforward generalization to the non-abelian case. We give some examples and apply the formalism to the case of SO(5) superconductivity.
Complete long-term corrosion protection with chemical vapor deposited grapheneMay 14 2018Despite the numerous reports on the topic, examples of chemical vapor deposited (CVD) graphene-based anticorrosive coatings able to provide long-term protection (i.e., several months) of metals are still unavailable. Here, we finally present a polymer-graphene ... More
The Battle of the Bulge: Decay of the Thin, False Cosmic StringOct 11 2013We consider the decay of cosmic strings that are trapped in the false vacuum in a theory of scalar electrodynamics in 3+1 dimensions. We restrict our analysis to the case of thin-walled cosmic strings which occur when large magnetic flux trapped inside ... More