Results for "W. P. Chen"

total 199728took 0.13s
Cavity QED characterization of many-body atomic states in double-well potentials -- The role of dissipationOct 31 2008Nov 04 2008When an incident light beam is scattered off a sample of ultracold atoms trapped in an optical lattice, the statistical properties of the retro-reflected field contain information about the quantum state of the atoms, and permit for example to distinguish ... More
Topological pairings in Janus monolayer TaSSeJul 23 2019The Janus monolayer transition metal dichalcogenides[TMDs] MXY[M=Mo,W, etc. and X,Y=S,Se, etc.] has been synthesized recently, and the Rashba spin splitting arises in it owing to the breaking of out-of-plane mirror symmetry[\href{https://journals.aps.org/prb/abstract/10.1103/PhysRevB.97.235404}{Phys. ... More
Discovery of Young Methane Dwarfs in the Rho Ophiuchi L 1688 Dark CloudSep 14 2015Sep 18 2015We report the discovery of two methane dwarfs in the dark cloud L 1688 of the Rho Oph star-forming region. The two objects were among the T dwarf candidates with possible methane absorption and cool atmospheres, as diagnosed by infrared colors using deep ... More
Magnetic correlations on the full chains of Ortho-II YBa$_2$Cu$_3$O$_{6.5}$Nov 26 2008Nov 27 2008We propose that the NMR line shape on the chain Cu in the stoichiometric high-$T_c$ superconductor Ortho-II YBa$_2$Cu$_3$O$_{6.5}$ is determined by the magnetization induced on Cu near O vacancies, due to strong magnetic correlations in the chains. An ... More
Morphology of Galactic Open ClustersAug 02 2004We analyzed the shapes of Galactic open clusters by the star counting technique with the 2MASS star catalog database. Morphological parameters such as the ellipticity and size have been derived via stellar density distribution, weighed by clustering probability. ... More
Search for and Characterization of Open Clusters Toward the Galactic Anti-center with Pan-STARRS1Sep 03 2013We have used a star-count algorithm based the Panoramic Survey Telescope And Rapid Response System 3$\pi$ survey data aim to identify and characterize uncharted open clusters (OCs). With limiting magnitudes of about 22 mag in \gps, \rps, \ips\ bands and ... More
The Lacerta OB1 AssociationNov 04 2008Lac OB1 is a nearby OB association in its final stage of star formation. While the member stars suggest an expansion time scale of tens of Myr, the latest star formation episode, as manifested by the existence of massive and pre-main sequence stars, took ... More
Triggered Star Formation by Massive StarsSep 13 2005Feb 03 2009We present our diagnosis of the role that massive stars play in the formation of low- and intermediate-mass stars in OB associations (the Lambda Ori region, Ori OB1, and Lac OB1 associations). We find that the classical T Tauri stars and Herbig Ae/Be ... More
Dynamics of a bistable Mott insulator to superfluid phase transition in cavity optomechanicsJun 22 2009Sep 29 2009We study the dynamics of the many-body state of ultracold bosons trapped in a bistable optical lattice in an optomechanical resonator controlled by a time-dependent input field. We focus on the dynamics of the many-body system following discontinuous ... More
Effect of collision dephasing on atomic evolutions in a high-Q cavityFeb 10 2003The decoherence mechanism of a single atom inside a high-Q cavity is studied, and the results are compared with experimental observations performed by M. Brune et al. [Phys. Rev. Lett. 76, 1800 (1996)]. Collision dephasing and cavity leakage are considered ... More
Nonlinear Magneto-Optics of Fe Monolayers from first principles: Structural dependence and spin-orbit coupling strengthSep 01 1997We calculate the nonlinear magneto-optical response of free-standing fcc (001), (110) and (111) oriented Fe monolayers. The bandstructures are determined from first principles using a full-potential LAPW method with the additional implementation of spin-orbit ... More
Cavity QED determination of atomic number statistics in optical latticesOct 05 2006Dec 14 2006We study the reflection of two counter-propagating modes of the light field in a ring resonator by ultracold atoms either in the Mott insulator state or in the superfluid state of an optical lattice. We obtain exact numerical results for a simple two-well ... More
Triggered Star Formation on the Border of the Orion-Eridanus SuperbubbleAug 10 2006Feb 03 2009A census of classical T Tauri stars and Herbig Ae/Be stars has been performed around the Orion-Eridanus Superbubble which is ionized and created by the Ori OB1 association. This sample is used to study the spatial distribution of newborn stars, hence ... More
Physics development of web-based tools for use in hardware clusters doing lattice physicsNov 08 2001Jefferson Lab and MIT are developing a set of web-based tools within the Lattice Hadron Physics Collaboration to allow lattice QCD theorists to treat the computational facilities located at the two sites as a single meta-facility. The prototype Lattice ... More
Lunar occultations of 184 stellar sources in two crowded regions towards the galactic bulgeMay 24 2011Lunar occultations (LO) provide a unique combination of high angular resolution and sensitivity at near-infrared wavelenghts. At the ESO Very Large Telescope, it is possible to achieve about 1 milliarcsecond (mas) resolution and detect sources as faint ... More
Is the CMB asymmetry due to the kinematic dipole?Aug 22 2011Jan 25 2012Parity violation found in the Cosmic Microwave Background (CMB) radiation is a crucial clue for the non-standard cosmological model or the possible contamination of various foreground residuals and/or calibration of the CMB data sets. In this paper, we ... More
Statistical Analysis of Filament Features Based on the Hα Solar Images from 1988 to 2013 by Computer Automated Detection MethodNov 15 2015We improve our filament automated detection method which was proposed in our previous works. It is then applied to process the full disk H$\alpha$ data mainly obtained by Big Bear Solar Observatory (BBSO) from 1988 to 2013, spanning nearly 3 solar cycles. ... More
Generation of entangled states of two atoms inside a leaky cavitySep 24 2003An in-depth theoretical study is carried out to examine the quasi-deterministic entanglement of two atoms inside a leaky cavity. Two $\Lambda$-type three-level atoms, initially in their ground states, may become maximally entangled through the interaction ... More
Search for and Characterization of Galactic Open Clusters with 2MASSNov 30 2011Feb 19 2012We have developed a star-counting algorithm and tested it on the 2MASS star catalog to search for density enhancements significantly above the field in Galactic latitude $|b|<50^{\circ}$. Nearly 500 open clusters are "rediscovered", along with 89 globular ... More
Evolutionary status of isolated B[e] starsJun 21 2016Aims. We study a sample of eight B[e] stars with uncertain evolutionary status to shed light on the origin of their circumstellar dust. Methods. We performed a diagnostic analysis on the spectral energy distribution beyond infrared wavelengths, and conducted ... More
The blue straggler population of the old open cluster Berkeley 17Feb 15 2019Blue Straggler Stars (BSSs) are observed in Galactic globular clusters and old open clusters. The radial distribution of BSSs has been used to diagnose the dynamical evolution of globular clusters. For the first time, with a reliable sample of BSSs identified ... More
A microscopic resolution of the chiral conundrum with crossing twin bands in Ag-106May 25 2019The nuclear chiral conundrum with crossing twin bands is investigated with three-dimensional tilted axis cranking covariant density functional theory in a fully self-consistent and microscopic way. The energy spectra and electromagnetic transition strengths ... More
Boundary knot method for Laplace and biharmonic problemsJul 28 2003The boundary knot method (BKM) [1] is a meshless boundary-type radial basis function (RBF) collocation scheme, where the nonsingular general solution is used instead of fundamental solution to evaluate the homogeneous solution, while the dual reciprocity ... More
Soft matter and fractional mathematics: insights into mesoscopic quantum and time-space structuresMay 16 2004Recent years have witnessed a great research boom in soft matter physics. by now, most advances, however, are of either empirical results or purely mathematical extensions. The major obstacle is lacking of insights into fundamental phsysical laws underlying ... More
A novel methodology of weighted residual for nonlinear computationsMay 02 1999One of strengths in the finite element (FE) and Galerkin methods is their capability to apply weak formulations via integration by parts, which leads to elements matching at lower degree of continuity and relaxes requirements of choosing basis functions. ... More
An explanation of infrared catastrophe of 1/f power spectraMay 09 2003Chen [1] builds the intrinsic link between the 1/f power spectra and the acoustic frequency power law dissipation and, accordingly, presents two explanations of the so-called infrared catastrophe of the 1/f power spectra. This note is an immediate follow-up. ... More
Determination of the effective strong coupling constant alpha_{s,g_1}(Q^2) from CLAS spin structure function dataMar 28 2008Jul 21 2008We present a new extraction of the effective strong coupling constant \alpha_{s,g_1}(Q^2). The result agrees with a previous determination and extends the measurement of the low and high Q^2 behavior of \alpha_{s,g_1}(Q^2) that was previously deduced ... More
Exact diagonalization analysis of the Anderson-Hubbard model and comparison to real-space self-consistent Hartree-Fock solutionsSep 26 2007Nov 17 2007We have obtained the exact ground state wave functions of the Anderson-Hubbard model for different electron fillings on a 4x4 lattice with periodic boundary conditions - for 1/2 filling such ground states have roughly 166 million states. When compared ... More
Experimental determination of the effective strong coupling constantSep 12 2005Jun 21 2007We present a first attempt to experimentally extract an effective strong coupling constant that we define to be a low Q2 extension of a previous definition by S. Brodsky et al. following an initial work of G. Grunberg. Using Jefferson Lab data and sum ... More
Triggered Star Formation in OB AssociationsNov 16 2006We present causal and positional evidence of triggered star formation in bright-rimmed clouds in OB associations, e.g., Ori OB1, and Lac OB1, by photoionization. The triggering process is seen also on a much larger scale in the Orion-Monoceros Complex ... More
A Universal Phase Diagram for PMN-xPT and PZN-xPTApr 11 2003The phase diagram of the Pb(Mg1/3Nb2/3)O3 and PbTiO3 solid solution (PMN-xPT) indicates a rhombohedral ground state for x < 0.32. X-ray powder measurements by Dkhil et al. show a rhombohedrally split (222) Bragg peak for PMN-10%PT at 80 K. Remarkably, ... More
Classical dynamics of the optomechanical modes of a Bose-Einstein condensate in a ring cavityFeb 23 2010We consider a cavity optomechanical system consisting of a Bose-Einstein condensate (BEC) interacting with two counterpropagating traveling-wave modes in an optical ring cavity. In contrast to the more familiar case where the condensate is driven by the ... More
Theory of Resistivity Upturns in Metallic CupratesMay 10 2009We propose that the experimentally observed resistivity upturn of cuprates at low temperatures may be explained by properly accounting for the effects of disorder in a strongly correlated metallic host. Within a calculation of the DC conductivity using ... More
Characterization of the Young Open Cluster G144.9+0.4 in the Camelopardalis OB1 AssociationAug 28 2013Sep 25 2013Our star-count analysis of the Two Micron All Sky Survey point sources resulted in an identification of the star cluster G144.9+0.4. The cluster was found, but not characterized, by Glushkova et al. We show that the cluster is physically associated with ... More
Some recent advances on the RBFJul 26 2002This paper aims to survey our recent work relating to the radial basis function (RBF) and its applications to numerical PDEs. We introduced the kernel RBF involving general pre-wavelets and scale-orthogonal wavelets RBF. A dimension-independent RBF error ... More
Positive time fractional derivativeOct 07 2002In mathematical modeling of the non-squared frequency-dependent diffusions, also known as the anomalous diffusions, it is desirable to have a positive real Fourier transform for the time derivative of arbitrary fractional or odd integer order. The Fourier ... More
A new definition of the fractional LaplacianSep 18 2002It is noted that the standard definition of the fractional Laplacian leads to a hyper-singular convolution integral and is also obscure about how to implement the boundary conditions. This purpose of this note is to introduce a new definition of the fractional ... More
A direct time-domain FEM modeling of broadband frequency-dependent absorption with the presence of matrix fractional power: Model IAug 20 2002The frequency-dependent attenuation of broadband acoustics is often confronted in many different areas. However, the related time domain simulation is rarely found in literature due to enormous technical difficulty. The currently popular relaxation models ... More
Pseudo-Newton method for nonlinear equationsJun 09 1999In order to avoid the evaluation of the Jacobian matrix and its inverse, the present author recently introduced the pseudo-Jacobian matrix with a general applicability of any nonlinear systems of equations. By using this concept, this paper proposes the ... More
Field-induced local moments around nonmagnetic impurities in metallic cupratesOct 30 2007We consider a defect in a strongly correlated host metal and discuss, within a slave boson mean field formalism for the $t-t'-J$ model, the formation of an induced paramagnetic moment which is extended over nearby sites. We study in particular an impurity ... More
Contact Binary Variables as X-ray SourcesAug 30 2005We present cross-identification of archived X-ray point sources with W UMa variable stars found in the All-Sky Automated Survey (ASAS). In a surveyed sky area of 300 square degrees of ASAS, 36 W UMa stars have been found associated with X-ray emission. ... More
The Influence of the Magnetic Field on the Properties of Neutron Star MatterMay 06 2005In the mean field approximation of the relativistic $\sigma$-$\omega$-$\rho$ model, the magnetic fields are incorporated, and its influence on the properties of n-p-e neutron star matter are studied. When the strength of the magnetic field is weaker than ... More
Hamiltonian chaos in a coupled BEC -- optomechanical cavity systemSep 29 2009We study a hybrid optomechanical system consisting of a Bose-Einstein condensate (BEC) trapped inside a single-mode optical cavity with a moving end-mirror. The intracavity light field has a dual role: it excites a momentum side-mode of the condensate, ... More
New high-sensitivity, milliarcsecond resolution results from routine observations of lunar occultations at the ESO VLTJul 15 2010(Abridged) Lunar occultations (LO) are a very efficient and powerful technique, that achieves the best combination of high angular resolution and sensitivity possible today at near-infrared wavelengths. Given that the events are fixed in time, that the ... More
The Stokes-Einstein Relation in Supercooled Aqueous Solutions of GlycerolNov 20 2006The diffusion of glycerol molecules decreases with decreasing temperature as its viscosity increases in a manner simply described by the Stokes-Einstein(SE) relation. Approaching the glass transition, this relation breaks down as it does with a number ... More
Propagators of the Jaynes-Cummings model in open systemsJan 18 2002Jan 21 2002We present a propagator formalism to investigate the scattering of photons by a cavity QED system that consists of a single two-level atom dressed by a leaky optical cavity field. We establish a diagrammatic method to construct the propagator analytically. ... More
Swapping and entangling qubits of single photons and atomsNov 23 2003A scheme is proposed here to achieve swapping and entangling of photonic and atomic qubits with high fidelity. The mechanism is based on the scattering of a single photon from a $\Lambda$-type three-level atom. The evolution of the coupled system is analyzed ... More
Time-space fabric underlying anomalous diffusionMay 08 2005This study unveils the time-space transforms underlying anomalous diffusion process. Based on this finding, we present the two hypotheses concerning the effect of fractal time-space fabric on physical behaviors and accordingly derive fractional quantum ... More
Levy stable distribution and [0,2] power law dependence of acoustic absorption on frequencyMay 09 2005The absorption of acoustic wave propagation in a broad variety of lossy media is characterized by an empirical power law function of frequency, w^y. It has long been noted that exponent y ranges from 0 to 2 for diverse media. Recently, the present author ... More
A modified BFGS quasi-Newton iterative formulaJul 14 1999The quasi-Newton equation is the very basis of a variety of the quasi-Newton methods. By using a relationship formula between nonlinear polynomial equations and the corresponding Jacobian matrix. presented recently by the present author, we established ... More
A new definition of nonlinear statistics mean and varianceJul 24 1999This note presents a new definition of nonlinear statistics mean and variance to simplify the nonlinear statistics computations. These concepts aim to provide a theoretical explanation of a novel nonlinear weighted residual methodology presented recently ... More
Mesoscopic Fractional Quantum in Soft MatterMay 09 2005Soft matter (e.g., biomaterials, polymers, sediments, oil, emulsions) has become an important bridge between physics and diverse disciplines. Its fundamental physical mechanism, however, is largely obscure. This study made the first attempt to connect ... More
A note on fractional derivative modeling of broadband frequency-dependent absorption: Model IIIAug 08 2002By far, the fractional derivative model is mainly related to the modelling of complicated solid viscoelastic material. In this study, we try to build the fractional derivative PDE model for broadband ultrasound propagation through human tissues.
1/f spectral trend and frequency power law of lossy mediaMay 07 2003The dissipation of acoustic wave propagation has long been found to obey an empirical power function of frequency, whose exponent parameter varies through different media. This note aims to unveil the inherent relationship between this dissipative frequency ... More
A note on radial basis function computingJun 03 2001This note carries three purposes involving our latest advances on the radial basis function (RBF) approach. First, we will introduce a new scheme employing the boundary knot method (BKM) to nonlinear convection-diffusion problem. It is stressed that the ... More
Does the Iron K$_α$ Line of Active Galactic Nuclei Arise from the Cerenkov Line-like Radiation?Sep 23 2003When thermal relativistic electrons with isotropic distribution of velocities move in a gas region, or impinge upon the surface of a cloud that consists of a dense gas or doped dusts, the Cerenkov effect produces peculiar atomic or ionic emission lines ... More
Gauge invariance, Lorentz covariance and canonical quantization in nucleon structure studiesNov 01 2014There are different operators of quark and gluon momenta, orbital angular momenta, and gluon spin in the nucleon structure study. The precise meaning of these operators are studied based on gauge invariance, Lorentz covariance and canonical quantization ... More
A negative dielectric constant in nano-particle materials under an electric field at very low frequenciesNov 07 2005The significance of a negative dielectric constant has long been recognized. We report here the observation of a field-induced large negative dielectric constant of aggregates of oxide nano-particles at frequencies below ~ 1 Hz at room temperature. The ... More
Field-induced giant static dielectric constant in nano-particle aggregates at room temperatureSep 20 2005The analogy between magnetism and electricity has long been established by Maxwell in the 19th century, in spite of their subtle difference. While magnetic materials display paramagnetism, ferromagnetism, antiferromagnetism, and diamagnetism, only paraelectricity, ... More
Coarse-graining renormalization by higher-order singular value decompositionJan 05 2012Aug 07 2012We propose a novel coarse graining tensor renormalization group method based on the higher-order singular value decomposition. This method provides an accurate but low computational cost technique for studying both classical and quantum lattice models ... More
Variability of young stellar objects in the star-forming region Pelican NebulaJun 01 2019We observed a field of $16'\times 16'$ in the star-forming region Pelican Nebula (IC 5070) at $BVRI$ wavelengths for 90 nights spread over one year in 2012-2013. More than 250 epochs in $VRI$-bands are used to identify and classify variables up to $V\sim ... More
Collective states of interacting ferromagnetic nanoparticlesNov 17 2005Discontinuous magnetic multilayers [CoFe/Al2O3] are studied by use of magnetometry, susceptometry and numeric simulations. Soft ferromagnetic Co80Fe20 nanoparticles are embedded in a diamagnetic insulating a-Al2O3 matrix and can be considered as homogeneously ... More
Characterization of Stellar and Substellar Members in the Coma Berenices Star ClusterJun 21 2018We have identified stellar and substellar members in the nearby star cluster Coma Berenices, using photometry, proper motions, and distances of a combination of 2MASS, UKIDSS, URAT1, and {\it Gaia}/DR2 data. Those with {\it Gaia}/DR2 parallax measurements ... More
Magnetic Moments of $J^P={3/2}^+$ PentaquarksDec 29 2003Jan 16 2004If the $J^P$ of $\Theta_5^+$ and $\Xi_5^{--}$ pentaquarks is really found to be ${1\over 2}^+$ by future experiments, they will be accompanied by $J^P={3\over 2}^+$ partners in some models. It is reasonable to expect that these $J^P={3\over 2}^+$ states ... More
Observation of pinning mode in Wigner solid of 1/3 fractional quantum Hall excitationsJun 11 2010Aug 20 2010We report the observation of a resonance in the microwave spectra of the real diagonal conductivities of a two-dimensional electron system within a range of ~ +- .0.015 $ from filling factor $\nu=1/3$. The resonance is remarkably similar to resonances ... More
Inelastic electron tunneling spectroscopy of nanoporous gold filmsJun 09 2014We investigated the localized electronic properties of nanoporous gold films by using an ultra-high vacuum scanning tunneling microscope at low temperature (4.2 K). Second derivative scanning tunneling spectroscopy shows the plasmon peaks of the nanoporous ... More
Spin-Orbit Coupling in Iridium-Based 5d Compounds Probed by X-ray Absorption SpectroscopyMay 30 2012We have performed x-ray absorption spectroscopy (XAS) measurements on a series of Ir-based 5d transition metal compounds, including Ir, IrCl3, IrO2, Na2IrO3, Sr2IrO4, and Y2Ir2O7. By comparing the intensity of the "white-line" features observed at the ... More
Two-dimensional Vortices in SuperconductorsJan 03 2007Superconductors have two key characteristics. They expel magnetic field and they conduct electrical current with zero resistance. However, both properties are compromised in high magnetic fields which can penetrate the material and create a mixed state ... More
Spin dependent electron-phonon interaction in SmFeAsO by low-temperature Raman spectroscopySep 26 2010Oct 07 2010The interplay between spin dynamics and lattice vibration has been suggested as an important part of the puzzle of high-temperature superconductivity. Here we report the strong interaction between spin fluctuation and phonon in SmFeAsO, a parent compound ... More
In-surface confinement of topological insulator nanowire surface statesMay 14 2015May 05 2016The bandstructures of [110] and [001] Bi2Te3 nanowires are solved with the atomistic 20 band tight binding functionality of NEMO5. The theoretical results reveal: The popular assumption that all topological insulator wire surfaces are equivalent is inappropriate. ... More
Carrier dynamics and infrared-active phonons in c-axis oriented RuSr$_2$GdCu$_2$O$_8$ filmMay 01 2001May 02 2001The conductivity spectra of c-axis oriented thin RuSr$_2$GdCu$_2$O$_8$ film on SrTiO$_3$ substrate, prepared by pulsed-laser deposition, are obtained from the analysis of the reflectivity spectra over broad frequency range and temperatures between 10 ... More
Magneto-Infrared Study of Topological Insulator Bi2Se3Aug 18 2015Aug 19 2015We present a magneto-infrared spectroscopic study of thin Bi2Se3 single crystal flakes. Magneto-infrared transmittance and reflectance measurements are performed in the Faraday geometry at 4.2K in a magnetic field up to 17.5T. Thin Bi2Se3 flakes (much ... More
The mode switching of PSR B2020+28May 21 2016This paper reports on polarimetric radiation properties based on the switching modes of normal PSR B2020+28 by analysing the data acquired from the Nanshan 25-m radio telescope at 1556 MHz. With nearly 8 hours quasi-continuous observation, the data presented ... More
Bistable Mott-insulator to superfluid phase transition in cavity optomechanicsFeb 14 2009May 04 2009We study the many-body state of ultracold bosons in a bistable optical lattice potential in an optomechanical resonator in the weak-coupling limit. New physics arises as a result of bistability and discontinuous jumps in the cavity field. Of particular ... More
A new polymorphic material? Structural degeneracy of ZrMn_2Mar 18 2004Based on density functional calculations, we propose that ZrMn_2 is a polymorphic material. We predict that at low temperatures the cubic C15, and the hexagonal C14 and C36 structures of the Laves phase compound ZrMn_2 are nearly equally stable within ... More
A combinatorial approach to metamaterials discoverySep 02 2010We report a high through-put combinatorial approach to photonic metamaterial optimization. The new approach is based on parallel synthesis and consecutive optical characterization of large numbers of spatially addressable nano-fabricated metamaterial ... More
Spatial-resolved X-ray photoelectron spectroscopy of Weyl semimetal NbAsFeb 25 2018We utilized X-ray photoemission electron microscopy (XPEEM) and X-ray photoelectron spectroscopy (XPS) to investigate the crystal surface of Weyl semimetal NbAs. XPEEM images present white and black contrast in both the Nb 3d and As 3d core level spectra. ... More
Heavy PentaquarksJan 24 2004Apr 02 2004We construct the spin-flavor wave functions of the possible heavy pentaquarks containing an anti-charm or anti-bottom quark using various clustered quark models. Then we estimate the masses and magnetic moments of the $J^P={1\over 2}^+$ or ${3\over 2}^+$ ... More
Fermi liquid breakdown and evidence for superconductivity in YFe$_2$Ge$_2$Nov 01 2013Sep 26 2014In the d-electron system YFe$_2$Ge$_2$, an unusually high and temperature dependent Sommerfeld ratio of the specific heat capacity $C/T \sim 100~\mathrm{mJ/(molK^2)}$ and an anomalous power law temperature dependence of the electrical resistivity $\rho ... More
Fluctuations of Entropy Production in Partially Masked Electric Circuits: Theoretical AnalysisJan 19 2016Jan 28 2016In this work we perform theoretical analysis about a coupled RC circuit with constant driven currents. Starting from stochastic differential equations, where voltages are subject to thermal noises, we derive time-correlation functions, steady-state distributions ... More
Problems related to gauge invariance and momentum, spin decomposition in nucleon structure studyDec 24 2013Dec 30 2013How do the quark and gluon share the nucleon momentum? How does the nucleon spin distribute among its constituents? What means the quark and gluon momentum, spin and orbital angular momentum? These problems are analyzed and a solution is proposed based ... More
The 50-100pc scale parent stellar populations of type II supernovae and limitations of single star evolution modelsJul 29 2019There is observational evidence of a dearth in core-collapse supernova (ccSN) explosions from stars with zero age main sequence (ZAMS) mass M_0~17-30 Msolar, referred to as the `red supergiant problem'. However, simulations now predict that above 20 Msolar, ... More
Pinning modes and interlayer correlation in high magnetic field bilayer Wigner solidsNov 27 2006We report studies of pinning mode resonances in the low total Landau filling (\nu) Wigner solid of a series of bilayer hole samples with negligible interlayer tunneling, and with varying interlayer separation d. Comparison of states with equal layer densities ... More
Abundances of neutron-capture elements in G 24-25. A halo-population CH subgiantMar 26 2012The differences between the neutron-capture element abundances of halo stars are important to our understanding of the nucleosynthesis of elements heavier than the iron group. We present a detailed abundance analysis of carbon and twelve neutron-capture ... More
Mode-coupling and polar nanoregions in the relaxor ferroelectric Pb(Mg1/3Nb2/3)O3Aug 09 2002We present a quantitative analysis of the phonon lineshapes obtained by neutron inelastic scattering methods in the relaxor ferroelectric Pb(Mg1/3Nb2/3)O3 (PMN). Differences in the shapes and apparent positions of the transverse acoustic (TA) and transverse ... More
A new activity phase of the blazar 3C 454.3. Multifrequency observations by the WEBT and XMM-Newton in 2007-2008Oct 14 2008We present and analyse the WEBT multifrequency observations of 3C 454.3 in the 2007-2008 observing season, including XMM-Newton observations and near-IR spectroscopic monitoring, and compare the recent emission behaviour with the past one. In the optical ... More
Timing Features of the Accretion--driven Millisecond X-Ray Pulsar XTE J1807--294 in 2003 March OutburstFeb 24 2006In order to probe the activity of the inner disk flow and its effect on the neutron star surface emissions, we carried out the timing analysis of the Rossi X-Ray Timing Explorer (RXTE) observations of the millisecond X-ray pulsar XTE J1807--294, focusing ... More
Investigating the Conditions of the Formation of a Type II Radio Burst on 2014 January 8Sep 19 2016It is believed that type II radio bursts are generated by shock waves. In order to understand the generation conditions of type II radio bursts, in this paper, we analyze the physical parameters of a shock front. The type II radio burst we selected was ... More
A Type II Radio Burst without a Coronal Mass EjectionMar 03 2015Type II radio bursts are thought to be a signature of coronal shocks. In this paper, we analyze a short-lived type II burst that started at 07:40 UT on 2011 February 28. By carefully checking white-light images, we find that the type II radio burst is ... More
Spin 3/2 PentaquarksMar 17 2005Jun 06 2005We investigate the possible existence of the spin 3/2 pentaquark states using interpolating currents with K-N color-octet structure in the framework of QCD finite energy sum rule (FESR). We pay special attention to the convergence of the operator product ... More
Stripe order from the perspective of the Hubbard modelSep 07 2017Apr 20 2018A microscopic understanding of the strongly correlated physics of the cuprates must account for the translational and rotational symmetry breaking that is present across all cuprate families, commonly in the form of stripes. Here we investigate emergence ... More
The critical temperature regions in resistive switchingOct 13 2011Aug 06 2012Critical temperature regions for resistive switching were found based on HfAlO resistive switching memory. From 5 K to 300 K, the resistive switching appears at 60 K, and then a reversible bipolar switching between the two states is observed at above ... More
Collimated Ultra-Bright Gamma-Rays from a PW-Laser-Driven Wire WigglerOct 31 2017Feb 16 2018It is shown by three-dimensional QED particle-in-cell simulation that as a laser pulse of 2.5 PW and 20 fs propagates along a sub-wavelength-wide solid wire, directional synchrotron $\gamma-$rays along the wire surface can be efficiently generated. With ... More
Mott insulator-to-metal transition in yttrium-doped CaIrO3May 02 2014Sep 25 2014We report on the study of insulator-to-metal transition in post-perovskite compound CaIrO3. It is discovered that a gradual chemical substitution of calcium by yttrium leads to the onset of strong metallic behavior in this compound. This observation is ... More
Variable stars in young open star cluster NGC 7380Nov 28 2015We present time series photometry of 57 variable stars in the cluster region NGC 7380. The association of these variable stars to the cluster NGC 7380 has been established on the basis of two colour diagrams and colour-magnitude diagrams. Seventeen stars ... More
Two-dimensional collective Hamiltonian for chiral and wobbling modes II: Electromagnetic transitionsSep 12 2018Sep 13 2018The intraband electromagnetic transitions in the framework of collective Hamiltonian for chiral and wobbling modes are calculated. By going beyond the mean field approximation on the orientations of rotational axis, the collective Hamiltonian provides ... More
Gravity Dual of Superconformal AnomalyAug 16 2005Jul 18 2007The supergravity dual of superconformal anomaly in a four-dimensional supersymmetric gauge theory is investigated. We consider a well-established dual correspondence between the ${\cal N}=1$ $SU(N+M)\times SU(N)$ supersymmetric gauge theory with two flavors ... More
Learning to Learn for Global Optimization of Black Box FunctionsNov 11 2016We present a learning to learn approach for training recurrent neural networks to perform black-box global optimization. In the meta-learning phase we use a large set of smooth target functions to learn a recurrent neural network (RNN) optimizer, which ... More
Learning to Learn for Global Optimization of Black Box FunctionsNov 11 2016Nov 29 2016We present a learning to learn approach for training recurrent neural networks to perform black-box global optimization. In the meta-learning phase we use a large set of smooth target functions to learn a recurrent neural network (RNN) optimizer, which ... More
Critiquing Variational Theories of the Anderson-Hubbard Model: Real-Space Self-Consistent Hartree-Fock SolutionsAug 28 2008A simple and commonly employed approximate technique with which one can examine spatially disordered systems when strong electronic correlations are present is based on the use of real-space unrestricted self-consistent Hartree-Fock wave functions. In ... More