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Results for "Z. Wang"

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A remark on the Hard Lefschetz Theorem for Kähler orbifoldsApr 08 2009We give a proof of the hard Lefschetz theorem for orbifolds that does not involve intersection homology. This answers a question of Fulton. We use a foliated version of the hard Lefschetz theorem due to El Kacimi.
On the Instability and Critical Damping Conditions, $kτ= 1/e$ and $kτ= π/2$ of the equation $\dotθ = -k θ(t-τ)$Apr 18 2014In this note, I show that it is possible to use elementary mathematics, instead of the machinery of Lambert function, Laplace Transform, or numerics, to derive the instability condition, $k \tau = \pi/2$, and the critical damping condition, $k\tau = 1/e$, ... More
Non-uniform Spatial Distribution of Spin Polarization in Topological Insulator (Bi2Te3) SurfaceDec 14 2014We found, through extensive study of micro reflectance difference spectroscopy images of Bi2Te3 topological insulator surface, the first clear experimental evidence that there is non-uniform spatial distribution of spin polarization (spin domains) in ... More
The Orbital Period of the Ultracompact Low-Mass X-Ray Binary 4U 1543--624Jun 21 2004Oct 26 2004We report the discovery of the orbital period of the ultracompact low-mass X-ray binary (LMXB) 4U 1543-624 using time-resolved optical photometry taken with the 6.5-m Clay (Magellan II) telescope in Chile. The light curve in the Sloan r' band clearly ... More
Using Drag to HoverApr 18 2003Unlike a helicopter, an insect can, in theory, use both lift and drag to stay aloft. Here we show that a dragonfly uses mostly drag to hover by employing asymmetric up and down strokes. Computations of a family of strokes further show that using drag ... More
Absence of Casimir regime in two-dimensional nanoribbon phonon conductionOct 25 2018In stark contrast with three-dimensional (3D) nanostructures, we show that boundary scattering in two-dimensional (2D) nanoribbons alone does not lead to a finite phonon mean free path. If combined with an intrinsic scattering mechanism, 2D boundary scattering ... More
New Physics of MetamaterialsApr 15 2014Einstein utilized Lorentz invariance from Maxwell's equations to modify mechanical laws and establish the special theory of relativity. Similarly, we may have a different theory if there exists another covariance of Maxwell's equations. In this paper, ... More
The Effects of the WISE/GALEX Photometry for the SED-Fitting with M31 Star Clusters and CandidatesSep 24 2017Spectral energy distribution (SED) fitting of stellar population synthesis models is an important and popular way to constrain the physical parameters ---e.g., the ages, metallicities, masses for stellar population analysis. The previous works suggest ... More
Single-photon transport in a one dimentional waveguide coupling to a hybrid atom-optomechanical systemAug 06 2013We explore theoretically the single-photon transport in a single-mode waveguide that is coupled to a hybrid atom-optomechanical system in a strong optomechanical coupling regime. Using a full quantum real-space approach, transmission and reflection coefficients ... More
Dynamical topological invariant for non-Hermitian Rice-Mele modelApr 26 2018We study a non-Hermitian Rice-Mele model without breaking time-reversal symmetry, with the non-Hermiticity arising from imbalanced hopping rates. The Berry connection, Berry curvature and Chern number are introduced in the context of biorthonormal inner ... More
Security Analysis of a Password-Based Authentication Protocol Proposed to IEEE 1363Jul 23 2012In recent years, several protocols for password-based authenticated key exchange have been proposed. These protocols aim to be secure even though the sample space of passwords may be small enough to be enumerated by an off-line adversary. In Eurocrypt ... More
Operator fidelity susceptibility: an indicator of quantum criticalityMar 20 2008Mar 28 2008We introduce the operator fidelity and propose to use its susceptibility for characterizing the sensitivity of quantum systems to perturbations. Two typical models are addressed: one is the transverse Ising model exhibiting a quantum phase transition, ... More
Transport through modes in random mediaOct 01 2012We show that the field speckle pattern of transmitted microwave radiation can be decomposed into a sum of patterns of the modes of the medium. We find strong correlation between modal field speckle patterns which leads to destructive interference between ... More
A variant transfer matrix method suitable for transport through multi-probe systemsNov 27 2007We have developed a variant transfer matrix method that is suitable for transport through multi-probe systems. Using this method, we have numerically studied the quantum spin Hall effect (QSHE) on 2D graphene with both intrinsic (Vso) and Rashba (Vr) ... More
Bounds of efficiency at maximum power for linear, superlinear and sublinear irreversible Carnot-like heat enginesOct 29 2011Apr 20 2012The efficiency at maximum power (EMP) of irreversible Carnot-like heat engines is investigated based on the weak endoreversible assumption and the phenomenologically irreversible thermodynamics. It is found that the weak endoreversible assumption can ... More
Efficiency at maximum power output of linear irreversible Carnot-like heat enginesAug 14 2011Dec 09 2011The efficiency at maximum power output of linear irreversible Carnot-like heat engines is investigated based on the assumption that the rate of irreversible entropy production of working substance in each "isothermal" process is a quadratic form of heat ... More
Search for Mid-IR Flux Variations from The Anomalous X-ray Pulsar 4U 0142+61Nov 01 2007We report on our Spitzer observations of the anomalous X-ray pulsar 4U 0142+61, made following a large X-ray burst that occurred on 2007 February 7. To search for mid-infrared flux variations, four imaging observations were carried out at 4.5 and 8.0 ... More
Partially dark optical molecule via phase controlAug 02 2016We study the tunable photonic distribution in an optical molecule consisting of two linearly coupled single-mode cavities. With the inter-cavity coupling and two driving fields, the energy levels of the optical-molecule system form a closed cyclic energy-level ... More
Computing Shortest Paths among Curved Obstacles in the PlaneMar 21 2011Apr 24 2015A fundamental problem in computational geometry is to compute an obstacle-avoiding Euclidean shortest path between two points in the plane. The case of this problem on polygonal obstacles is well studied. In this paper, we consider the problem version ... More
Landau Theory of the Phase Transitions in Half Doped Manganites: Interplay of Magnetic, Charge and Structural OrdersOct 27 1999The order parameters of the magnetic, charge and structural orders at half-doped manganites are identified. A corresponding Landau theory of the phase transitions is formulated. Many structural and thermodynamical behaviors are accounted for and clarified ... More
Symmetry Origin of the Phase Transitions and Phase Separation in Manganites at Low DopingOct 27 1999We analyze the symmetry changes of the paramagnetic to the A-type antiferromagnetic and to the ferromagnetic phase transitions in undoped and moderately doped LaMnO$_3$, respectively. We show that in the orthorhombic-distorted perovskite manganites the ... More
Fully Complex MagnetoencephalographyAug 25 2005Complex numbers appear naturally in biology whenever a system can be analyzed in the frequency domain, such as physiological data from magnetoencephalography (MEG). For example, the MEG steady state response to a modulated auditory stimulus generates ... More
Revealing Majorana Fermion states in a superfluid of cold atoms subject to a harmonic potentialAug 24 2012We here explore Majorana Fermion states in an s-wave superfluid of cold atoms in the presence of spin-orbital coupling and an additional harmonic potential. The superfluid boundary is induced by a harmonic trap. Two locally separated Majorana Fermion ... More
Weak Visibility Queries of Line Segments in Simple PolygonsDec 25 2012Given a simple polygon P in the plane, we present new algorithms and data structures for computing the weak visibility polygon from any query line segment in P. We build a data structure in O(n) time and O(n) space that can compute the visibility polygon ... More
Computing L1 Shortest Paths among Polygonal Obstacles in the PlaneFeb 26 2012Given a point $s$ and a set of $h$ pairwise disjoint polygonal obstacles of totally $n$ vertices in the plane, we present a new algorithm for building an $L_1$ shortest path map of size O(n) in $O(T)$ time and O(n) space such that for any query point ... More
Quantum simulation of topological Majorana bound states and their universal quantum operations using charge-qubit arraysMar 18 2014Mar 13 2015Majorana bound states have been a focus of condensed matter research for their potential applications in topological quantum computation. Here we utilize two charge-qubit arrays to explicitly simulate a DIII class one-dimensional superconductor model ... More
Protecting dissipative quantum state preparation via dynamical decouplingMar 12 2013We show that dissipative quantum state preparation processes can be protected against qubit dephasing by interlacing the state preparation control with dynamical decoupling (DD) control consisting of a sequence of short $\pi$-pulses. The inhomogeneous ... More
Fourier Analysis and Evaluation of DG, FD and Compact Difference Methods for Conservation LawsFeb 08 2018Large eddy simulation (LES) has been increasingly used to tackle vortex-dominated turbulent flows. In LES, the quality of the simulation results hinges upon the quality of the numerical discretizations in both space and time. It is in this context we ... More
Manipulating Cooper pairs with a controllable momentum in periodically driven degenerate Fermi gasesOct 15 2018We here present an experimentally feasible proposal for manipulating Cooper pairs in degenerate Fermi gases trapped by an optical lattice. Upon introducing an \textit{in situ} periodically driven field, the system may be described by an effective time-independent ... More
An Improved Algorithm for Reconstructing a Simple Polygon from the Visibility AnglesSep 13 2010In this paper, we study the following problem of reconstructing a simple polygon: Given a cyclically ordered vertex sequence of an unknown simple polygon P of n vertices and, for each vertex v of P, the sequence of angles defined by all the visible vertices ... More
A minimum single-band model for low-energy excitations in superconducting K$_x$Fe$_2$Se$_2$Aug 17 2011We propose a minimum single-band model for the newly discovered iron-based superconducting K$_x$Fe$_2$Se$_2$. Our model is found to be numerically consistent with the five-orbital model at low energies. Based on our model and the random phase approximation, ... More
An Adaptive Descriptor Design for Object Recognition in the WildMay 01 2013Digital images nowadays have various styles of appearance, in the aspects of color tones, contrast, vignetting, and etc. These 'picture styles' are directly related to the scene radiance, image pipeline of the camera, and post processing functions. Due ... More
Time in Quantum Mechanics and Quantum Field TheoryNov 08 2002W. Pauli pointed out that the existence of a self-adjoint time operator is incompatible with the semibounded character of the Hamiltonian spectrum. As a result, people have been arguing a lot about the time-energy uncertainty relation and other related ... More
Impurity states in antiferromagnetic Iron ArsenidesSep 04 2008We explore theoretically impurity states in the antiferromagnetic spin-density wave state of the iron arsenide. Two types of impurity models are employed: one has only the intraband scattering while the other has both the intraband and interband scattering ... More
Nuclear Spin Relaxation Rate of Disordered $p_x+ip_y$-wave SuperconductorsAug 08 2003Based on an effective Hamiltonian with the binary alloy disorder model defined in the triangular lattice, the impurity scattering effects on the density of states and especially on the spin-lattice relaxation rate $1/T_1$ of $p_x+ip_y$-wave superconductors ... More
The application of precision time protocol on EAST timing systemJun 24 2018The timing system focuses on synchronizing and coordinating each subsystem according to the trigger signals. A new prototype timing slave node based on precision time protocol has been developed by using ARM STM32 platform. The proposed slave timing module ... More
CHIP: Channel-wise Disentangled Interpretation of Deep Convolutional Neural NetworksFeb 07 2019With the widespread applications of deep convolutional neural networks (DCNNs), it becomes increasingly important for DCNNs not only to make accurate predictions but also to explain how they make their decisions. In this work, we propose a CHannel-wise ... More
Symmetry Does Not Allow Canting of Spins in La_{1.4}Sr_{1.6}Mn_2O_7Jan 14 2000We analyze the symmetry of all possible magnetic structures of bilayered manganites La_{2-2x}Sr_{1+2x}Mn_2O_7 with doping 0.3 <= x < 0.5 and formulate a corresponding Landau theory of the phase transitions involved. It is shown that canting of spins is ... More
Gamma-Ray Burst Afterglows with Energy Injection: Homogeneous Versus Wind External MediaMar 18 2001Jun 12 2001Assuming an adiabatic evolution of a gamma-ray burst (GRB) fireball interacting with an external medium, we calculate the hydrodynamics of the fireball with energy injection from a strongly magnetic millisecond pulsar through magnetic dipole radiation, ... More
Pairing Symmetry and Spin Excitations of Iron Selenide SuperconductorsFeb 08 2012We propose an effective single-band model for the newly discovered iron selenide superconductors A$_x$Fe$_{2-y}$Se$_2$ (A=Tl,K,Rb,Cs). Based on this minimum model and the random phase approximation, the $d_{x^2-y^2}$ pairing symmetry is revealed theoretically, ... More
Bounds of Efficiency at Maximum Power for Normal-, Sub- and Super-Dissipative Carnot-Like Heat EnginesJan 04 2012Jan 24 2013The Carnot-like heat engines are classified into three types (normal-, sub- and super-dissipative) according to relations between the minimum irreversible entropy production in the "isothermal" processes and the time for completing those processes. The ... More
Velocity Probability Distribution Function in the Crossover and the Viscous RangeJan 28 1997We derive a multifractal model for the velocity probability density distribution function (PDF), which is valid from the inertial range to the viscous range. The model gives a continuous evolution of velocity PDFs from large to small scales. It also predicts ... More
Phenomenological theory of spin excitations in La- and Y-based cupratesApr 08 2007Motivated by recent inelastic neutron scattering (INS) experiments on La-based cuprates and based on the fermiology theories, we study the spin susceptibility for La-based (e.g., La$_{2-x}$Sr$_x$CuO$_4$) and Y-based (e.g., YBa$_2$Cu$_3$O$_y$) cuprates, ... More
Probing the superconducting pairing symmetry from spin excitations in BiS$_2$ based superconductorsAug 06 2012Starting from a two-orbital model and based on the random phase approximation, spin excitations in the superconducting state of the newly discovered BiS$_2$ superconductors with three possible pairing symmetries are studied theoretically. We show that ... More
Is the dispersion anomaly of the electron spectrum induced by the charge-density-wave in high-$T_c$ superconductors?Dec 16 2006We propose that the presence of a rotationally symmetric charge density wave (CDW) with the modulation of 4-lattice constant in high-$T_c$ superconductors is essentially responsible for an anomalous quasiparticle dispersion revealed recently by angle-resolved ... More
GeV Emission during X-Ray Flares from Late Internal Shocks: Application to GRB 100728AAug 06 2013Recently, the GeV radiation during the X-ray flare activity in GRB 100728A was detected by Feimi/LAT. Here we study the dynamics and emission properties of collision between two homogeneous shells based on the late internal shock model. The GeV photons ... More
On the Accuracy and Stability of Various DG Formulations for DiffusionOct 07 2018In this paper, we study the stability (in terms of the maximum time step) and accuracy (in terms of the wavenumber-diffusion properties) for several popular discontinuous Galerkin (DG) viscous flux formulations. The considered methods include the symmetric ... More
Verification of particle simulation of radio frequency waves in fusion plasmasOct 05 2017Radio frequency (RF) waves can provide heating, current and flow drive, as well as instability control for steady state operations of fusion experiments. A particle simulation model has been developed in this work to provide a first-principles tool for ... More
Limit cycle induced frequency locking in self-sustained current oscillations of superlatticesApr 29 2003The ac response of self-sustained current oscillations (SSCOs) in GaAs/AlAs superlattices (SLs) is derived based on the deformation of a limit cycle under an external ac driving force. Frequency locking into an integer fraction of the ac frequency is ... More
A possible minimum toy model with negative differential capacitance for self-sustained current oscillationDec 16 2005Feb 16 2006We generalize a simple model for superlattices to include the effect of differential capacitance. It is shown that the model always has a stable steady-state solution (SSS) if all differential capacitances are positive. On the other hand, when negative ... More
Nonlinear electromagnetic formulation for particle simulation of lower hybrid waves in toroidal geometryFeb 21 2016Electromagnetic particle simulation model has been formulated and verified for nonlinear processes of lower hybrid (LH) waves in fusion plasmas. Electron dynamics is described by the drift kinetic equation using either kinetic momentum or canonical momentum. ... More
Spin transfer torque enhancement in dual spin valve in the ballistic regimeJun 21 2010Sep 22 2010The spin transfer torque in all-metal dual spin valve, in which two antiparallelly aligned pinned ferromagnetic layers are on the two sides of a free ferromagnetic layer with two thin nonmagnetic spacers in between, is studied in the ballistic regime. ... More
Current-induced domain wall motion with adiabatic spin torque only in cylindrical nanowiresMar 21 2010We investigate current-driven domain wall (DW) propagation in magnetic nanowires in the framework of the modified Landau-Lifshitz-Gilbert equation with both adiabatic and nonadiabatic spin torque (NAST) terms. Contrary to the common opinion that NAST ... More
Analysis of the strong coupling constant $G_{D_{s}^{*}D_{s}φ}$ and the decay width of $D_{s}^{*}\rightarrow D_{s}γ$ with QCD sum rulesJan 18 2015In this article, we calculate the form factors and the coupling constant of the vertex $D_{s}^{*}D_{s}\phi$ using the three-point QCD sum rules. We consider the contributions of the vacuum condensates up to dimension $7$ in the operator product expansion(OPE). ... More
Optimal time-dependent polarized current pattern for fast domain wall propagation in nanowires: Exact solutions for biaxial and uniaxial anisotropiesApr 22 2010One of the important issues in nanomagnetism is to lower the current needed for a technologically useful domain wall (DW) propagation speed. Based on the modified Landau-Lifshitz-Gilbert (LLG) equation with both Slonczewski spin-transfer torque and the ... More
Tunable one-dimensional microwave emissions from cyclic-transition three-level atomsOct 29 2010By strongly driving a cyclic-transition three-level artificial atom, demonstrated by such as a flux-based superconducting circuit, we show that coherent microwave signals can be excited along a coupled one-dimensional transmission line. Typically, the ... More
Dynamical bulk-edge correspondence for nodal lines in parameter spaceJan 04 2018Nodal line in parameter space, at which the energy gap closes up, can either be the boundary separating two topological quantum phases or two conventional phases. We study the topological feature of nodal line in parameter space via a dimerized Kitaev ... More
Exotic Topological Types of Majorana Zero-modes and Their Universal Quantum ManipulationMay 16 2013Jan 19 2014From our general index theorem that characterises faithfully the boundary-bulk correspondence of topological superconductors and insulators, we reveal rigorously that four topologically distinct types of Majorana zero-modes can emerge at the ends of superconducting ... More
The relationships of solar flares with both sunspot and geomagnetic activityDec 24 2011The relationships between solar flare parameters (total importance, time duration, flare index, and flux) and sunspot activity (Rz) as well as those between geomagnetic activity (aa index) and the flare parameters can be well described by an integral ... More
Quantum interference in the fluorescence of a molecular systemSep 20 1999It has been observed experimentally [H.R. Xia, C.Y. Ye, and S.Y. Zhu, Phys. Rev. Lett. {\bf 77}, 1032 (1996)] that quantum interference between two molecular transitions can lead to a suppression or enhancement of spontaneous emission. This is manifested ... More
Energy spectra of three electrons in Si/SiGe single and vertically coupled double quantum dotsNov 03 2011We study three-electron energy spectra in Si/SiGe single and vertically coupled double quantum dots where all the relevant effects, such as, the Zeeman splitting, spin-orbit coupling, valley coupling and electron-electron Coulomb interaction are explicitly ... More
Power Minimization in Multi-pair Two-Way RelayingJun 24 2013Sep 03 2014This doc provides some proofs in our submitted journal paper.
Measuring the degree of unitarity for any quantum processApr 02 2014Quantum processes can be divided into two categories: unitary and non-unitary ones. For a given quantum process, we can define a \textit{degree of the unitarity (DU)} of this process to be the fidelity between it and its closest unitary one. The DU, as ... More
Tuning Transport Properties of Topological Edge States of Bi(111) Bilayer Film by Edge AdsorptionFeb 27 2014Based on first-principles and tight-binding calculations, we report that the transport properties of topological edge states of zigzag Bi(111) nanoribbon can be significantly tuned by H edge adsorption. The Fermi velocity is increased by one order of ... More
Real-time 2D/3D Registration via CNN RegressionJul 27 2015Apr 25 2016In this paper, we present a Convolutional Neural Network (CNN) regression approach for real-time 2-D/3-D registration. Different from optimization-based methods, which iteratively optimize the transformation parameters over a scalar-valued metric function ... More
Exotic Haldane Superfluid Phase of Soft-Core Bosons in Optical LatticesMay 26 2015May 03 2016We propose to realize an exotic Haldane superfluid (HSF) phase in an extended Bose-Hubbard model on the two-leg ladder (i.e., a two-species mixture of interacting bosons). The proposal is confirmed by means of large-scale quantum Monte Carlo simulations, ... More
Disordered Weyl semimetals and their topological familyDec 24 2014Apr 24 2015We develop a topological theory for disordered Weyl semimetals in the framework of gauge invariance of replica formalism and boundary-bulk correspondence of Chern insulators. An anisotropic topological $\theta$-term is analytically derived for the effective ... More
Automorphisms of strongly regular graphsNov 13 2014In this article we generalize a theorem of Benson for generalized quadrangles to strongly regular graphs and directed strongly regular graphs. The main result provides numerical restrictions on the number of fixed vertices and the number of vertices mapped ... More
Dynamical Mean-Field Solution for a Model of Metal-Insulator Transitions in Moderately Doped ManganitesOct 27 1999We propose that a specific spatial configuration of lattice sites that energetically favor {\it 3+} or {\it 4+} Mn ions in moderately doped manganites constitutes approximately a spatially random two-energy-level system. Such an effect results in a mechanism ... More
Practically secure quantum bit commitment based on quantum sealsApr 22 2008The relationship between the quantum bit commitment (QBC) and quantum seal (QS) is studied. It is elaborated that QBC and QS are not equivalent, but QS protocols satisfying a stronger unconditional security requirement can lead to an unconditionally secure ... More
PTF11agg as the First Evidence for Reverse Shock Emission from a Postmerger Millisecond MagnetarAug 06 2013Aug 10 2013Based on the stiff equations of state of neutron stars (NS) and the discovery of high-mass NSs, a NS-NS merger will leave behind, with high probabilities, a rapidly rotating massive magnetar. The central magnetar will dissipate its rotational energy to ... More
The distribution of two-dimensional eccentricity of Sunyaev-Zeldovich Effect and X-ray surface brightness profilesSep 07 2004Sep 08 2004With the triaxial density profile of dark matter halos and the corresponding equilibrium gas distribution, we derive two-dimensional Sunyaev-Zeldovich (SZ) effect and X-ray surface brightness profiles for clusters of galaxies. It is found that the contour ... More
An additive and operational entanglement measure: conditional entanglement of mutual informationApr 23 2008Oct 30 2008Based on the monogamy of entanglement, we develop the technique of quantum conditioning to build an {\it additive} entanglement measure: the conditional entanglement of mutual information. Its {\it operational} meaning is elaborated to be the minimal ... More
Two-Point $L_1$ Shortest Path Queries in the PlaneMar 13 2014Let $\mathcal{P}$ be a set of $h$ pairwise-disjoint polygonal obstacles with a total of $n$ vertices in the plane. We consider the problem of building a data structure that can quickly compute an $L_1$ shortest obstacle-avoiding path between any two query ... More
Superconductivity in doped inversion-symmetric Weyl semimetalsOct 05 2015We study theoretically the superconductivity in doped Weyl semimetals with an inversion symmetry based on the Bogoliubov-de Gennes equations. In principle, the two superconducting states, i.e., the zero momentum BCS-like pairing and the finite momentum ... More
Detecting competing orders through the edge states in the heterostructures with high-Tc superconductorsOct 08 2018Considering a $d$-wave superconductor being in proximity to a two-dimensional Weyl model, a topological superconductor with gapless edge states may be realized. We here demonstrate that the system can become topologically trivial when an additional d-density-wave ... More
Resolving different pairing states in Weyl superconductors through the single-particle spectrumMay 28 2018We study theoretically single-particle spectra of Weyl superconductors. Three different superconducting pairing states are addressed, which are the BCS-type states with the $s$-wave pairing symmetry and the $p+ip$-wave pairing symmetry, and the FFLO pairing ... More
A universal scaling law of black hole activity including gamma-ray burstsMay 24 2017Previous works show that a correlation among radio luminosity, X-ray luminosity, and black hole (BH) mass from stellar-mass BHs in X-ray binaries to supermassive BHs in active galactic nuclei (AGNs), which leads to the so-called fundamental plane of BH ... More
Unified theory of phase separation and charge ordering in doped manganite perovskitesJun 09 1999A unified theory is developed to explain various types of electronic collective behaviors in doped manganites R$_{1-x}$X$_x$MnO$_3$ (R = La, Pr,Nd etc. and X = Ca, Sr, Ba etc.). Starting from a realistic electronic model, we derive an effective Hamiltonianis ... More
Antiferromagnetism and phase separation in electronic models for doped transition-metal oxidesMar 25 1998Aug 24 1998We investigate the ground state properties of electronic models for doped manganites and nickelates. An effective t - J like Hamiltonian is derived from the case of strong Hund coupling between the conduction electrons and localized spins by means of ... More
Spatial reflection and renormalization group flow of quantum many-body systems with matrix product state representationJul 28 2007Mar 31 2008The property of quantum many-body systems under spatial reflection and the relevant physics of renormalization group (RG) procedure are revealed. By virtue of the matrix product state (MPS) representation, various attributes for translational invariant ... More
Diffusion in a Random Velocity Field: Spectral Properties of a Non-Hermitian Fokker-Planck OperatorApr 23 1997We study spectral properties of the Fokker-Planck operator that describes particles diffusing in a quenched random velocity field. This random operator is non-Hermitian and has eigenvalues occupying a finite area in the complex plane. We calculate the ... More
A meshless method for compressible flows with the HLLC Riemann solverFeb 11 2014The HLLC Riemann solver, which resolves both the shock waves and contact discontinuities, is popular to the computational fluid dynamics community studying compressible flow problems with mesh methods. Although it was reported to be used in meshless methods, ... More
Exceptional point induced lasing dynamics in a non-Hermitian systemAug 22 2018Non-Hermitian systems exhibit many peculiar dynamic behaviors which never showed up in Hermitian systems. The existence of spectral singularity (SS) for a non-Hermitian scattering center provides a lasing mechanism in the context of quantum mechanics. ... More
Study of the decay mechanism for B+ to p pbar K+ and B+ to p pbar pi+Jun 28 2007Oct 15 2007We study the characteristics of the low mass ppbar enhancements near threshold in the three-body decays B+ to p pbar K+ and B+ to p pbar pi+. We observe that the proton polar angle distributions in the ppbar helicity frame in the two decays have the opposite ... More
Pseudogap and Fermi-arc Evolution in the Phase-fluctuation ScenarioMay 30 2010Pseudogap phenomena and the formation of Fermi arcs in underdoped cuprates are numerically studied in the presence of phase fluctuations that are simulated by an XY model. Most importantly the spectral function for each Monte Carlo sample is calculated ... More
Spectrum of the Fokker-Planck operator representing diffusion in a random velocity fieldJun 18 1999We study spectral properties of the Fokker-Planck operator that represents particles moving via a combination of diffusion and advection in a time-independent random velocity field, presenting in detail work outlined elsewhere [J. T. Chalker and Z. J. ... More
Spectral Efficiency of the Cellular Two-Way Relaying with Large Antenna ArraysSep 03 2014This paper considers a multiuser cellular two-way relay network (cTWRN) where multiple users exchange information with a base station (BS) via a relay station (RS). Each user is equipped with a single antenna, while both the BS and the RS are equipped ... More
Structure of the $D_{s0}(2317)$ and the strong coupling constant $g_{D_{s0} D K}$ with the light-cone QCD sum rulesMar 01 2006May 03 2006In this article, we take the point of view that the charmed scalar meson $D_{s0}(2317)$ is the conventional $c\bar{s}$ meson and calculate the strong coupling constant $g_{D_{s0} D K}$ within the framework of the light-cone QCD sum rules approach. The ... More
Dynamical symmetry breaking, confinement with flat-bottom potentialApr 14 2002In this article, we calculate the dressed quark propagator with the flat bottom potential in the framework of the rain-bow Schwinger-Dyson equation. Then based on the nonperturbative dressed quark propagator, we calculate the $\pi$ decay constant and ... More
On the conservation of spin currents in spin-orbit coupled systemsDec 15 2005Applying the Gordon-decomposition-like technique, the convective spin current (CSC) is extracted from the total angular-momentum current. The CSC describes the transport properties of the electron spin and is conserved in the relativistic quantum mechanics ... More
A Simulated Annealing based Inexact Oracle for Wasserstein Loss MinimizationAug 12 2016Learning under a Wasserstein loss is an emerging research topic. We call collectively the problems formulated under this framework Wasserstein Loss Minimization (WLM). One important appeal of WLM is the innate capability to account for the prior similarity ... More
General Electrical Manipulations of Electron SpinApr 02 2005Traditionally, the interactions related to the 3D spatial angular momentum have been studied completely, while the ones related to the generators of Lorentz boost are always ignored. In this paper we show that the generators of Lorentz boost have a nontrivial ... More
Extended JC-Dicke model for a two-component atomic BEC inside a cavityApr 30 2009Feb 25 2010We consider a trapped two-component atomic Bose-Einstein condensate (BEC), where each atom with three energy-levels is coupled to an optical cavity field and an external classical optical field as well as a microwave field to form the so-called $\Delta$-type ... More
The Gassner representation for string linksJun 08 1998The Gassner representation of the pure braid group to $GL_n(Z[Z^n])$ can be extended to give a representation of the concordance group of $n$-strand string links to $GL_n(F)$, where $F$ is the field of quotients of $\zz[\zz^n]$, $ F = Q(t_1,...,t_n)$; ... More
First evidence of a strong Magneto-capacitance coupling at room temperature in integrated piezoelectric resonatorsNov 10 2004In the vicinity of their resonance frequency, piezoelectric resonators are highly sensitive to small perturbations. The present report is focussed on the magnetic field as a perturbation source. First, magneto-dielectric modulation of more than 10% is ... More
Long GRBs are metallicity-biased tracers of star formation: evidence from host galaxies and redshift distributionJun 03 2014We investigate the mass distribution of long gamma-ray burst (GRB) host galaxies and the redshift distribution of long GRBs by considering that long GRBs occur in low-metallicity environments. We calculate the upper limit on the stellar mass of a galaxy ... More
Weak gravitational lensing effects on cosmological parameters and dark energy from gamma-ray burstsDec 17 2011Gamma-ray bursts (GRBs) are attractive objects for constraining the nature of dark energy in a way complementary to other cosmological probes, especially at high redshifts. However, the apparent magnitude of distant GRBs can be distorted by the gravitational ... More
Self-organized criticality in X-ray flares of gamma-ray burst afterglowsAug 06 2013X-ray flares detected in nearly half of gamma-ray burst (GRB) afterglows are one of the most intriguing phenomena in high-energy astrophysics. All the observations indicate that the central engines of bursts, after the gamma-ray emission has ended, still ... More