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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.
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
Irreversible Temperature Quenching and Antiquenching of Photoluminescence of ZnS/CdS:Mn/ZnS Quantum Well Quantum DotsSep 19 2013An experimental observation on irreversible thermal quenching and antiquenching behavior is reported for photoluminescence (PL) of ZnS/CdS:Mn/ZnS quantum well quantum dots (QWQDs) prepared with a reverse micelle method. The dual-color emissions, a blue ... More
Does a low solar cycle minimum hint at a weak upcoming cycle?Aug 14 2010The maximum amplitude (Rm) of a solar cycle, in the term of mean sunspot numbers, is well-known to be positively correlated with the preceding minimum (Rmin). So far as the long term trend is concerned, a low level of Rmin tends to be followed by a weak ... More
General response theory of topologically stable Fermi points and its implications for disordered casesApr 09 2015Aug 25 2015We develop a general response theory of gapless Fermi points with nontrivial topological charges for gauge and nonlinear sigma fields, which asserts that the topological character of the Fermi points is embodied as the terms with discrete coefficients ... More
T-shaped Single-photon RouterSep 10 2014Aug 26 2015We study the transport properties of a single photon scattered by a two-level system (TLS) in a T-shaped waveguide, which is made of two coupled-resonator waveguides (CRWs)--- an infinite CRW and a semi-infinite CRW. The spontaneous emission of the TLS ... More
A Generic Two-band Model for Unconventional Superconductivity and Spin-Density-Wave Order in Electron and Hole Doped Iron-Based SuperconductorsMar 31 2008Apr 12 2008Based on experimental data on the newly synthesized iron-based superconductors and the relevant band structure calculations, we propose a minimal two-band BCS-type Hamiltonian with the interband Hubbard interaction included. We illustrate that this two-band ... More
Testing the anisotropy of cosmic acceleration from Pantheon supernovae sampleMay 23 2018Jul 04 2018In this paper, we study the anisotropy of cosmic acceleration the using Pantheon sample, which includes 1048 spectroscopically confirmed Type Ia supernovae (SNe Ia) covering the redshift range $0.01 < z < 2.3$. In hemisphere comparison method, we find ... More
Performance of General STCs over Spatially Correlated MIMO Single-keyhole ChannelsNov 14 2013Jan 13 2014For MIMO Rayleigh channels, it has been shown that transmitter correlations always degrade the performance of general space-time codes (STCs) in high SNR regimes. In this correspondence, however, we show that when MIMO channels experience single-keyhole ... More
Topological Classification and Stability of Fermi SurfacesNov 30 2012Jun 26 2013In the framework of the Cartan classification of Hamiltonians, a kind of topological classification of Fermi surfaces is established in terms of topological charges. The topological charge of a Fermi surface depends on its codimension and the class to ... More
Experimental implementation of high-fidelity unconventional geometric quantum gates using NMR interferometerDec 05 2005Following a key idea of unconventional geometric quantum computation developed earlier [Phys. Rev. Lett. 91, 197902 (2003)], here we propose a more general scheme in such an intriguing way: $\gamma_{d}=\alpha_{g}+\eta \gamma _{g}$, where $\gamma_{d}$ ... More
Bilinear forms on Green rings of finite dimensional Hopf algebrasDec 17 2015Apr 01 2016In this paper, we study the Green ring and the stable Green ring of a Hopf algebra $H$ by means of bilinear forms. We show that the Green ring of a Hopf algebra of finite representation type is a Frobenius algebra over $\mathbb{Z}$ with a dual basis associated ... More
Constraining Dark Energy and Cosmological Transition Redshift with Type Ia SupernovaeAug 30 2007The property of dark energy and the physical reason for acceleration of the present universe are two of the most difficult problems in modern cosmology. The dark energy contributes about two-thirds of the critical density of the present universe from ... More
Efficient Algorithms for One-Dimensional k-Center ProblemsJan 31 2013Mar 06 2014We consider the problem of finding k centers for n weighted points on a real line. This (weighted) k-center problem was solved in O(n log n) time previously by using Cole's parametric search and other complicated approaches. In this paper, we present ... 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
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
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
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
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
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
Nonsingular bounce cosmology from general relativityApr 22 2019We investigate a particular classical nonsingular bounce cosmology, which results from general relativity if we allow for degenerate metrics. The simplest model has a constant equation of state and we calculate the modified Hubble diagram for both the ... More
Simple unconventional geometric scenario of one-way quantum computation with superconducting qubits inside a cavityMar 12 2007Apr 23 2007We propose a simple unconventional geometric scenario to achieve a kind of nontrivial multi-qubit operations with superconducting charge qubits placed in a microwave cavity. The proposed quantum operations are insensitive not only to the thermal state ... More
Microwave conductance in random waveguides in the crossover to Anderson localization and single parameter scalingMar 05 2013Feb 17 2014The nature of transport of electrons and classical waves in disordered systems depends upon the proximity to the Anderson localization transition between freely diffusing and localized waves. The suppression of average transport and the enhancement of ... More
Biharmonic maps into Sol and Nil spacesDec 13 2006In this paper, we study biharmonic maps into Sol and Nil spaces, two model spaces of Thurston's 3-dimensional geometries. We characterize non-geodesic biharmonic curves in Sol space and prove that there exists no non-geodesic biharmonic helix in Sol space. ... 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
Improved superlensing in two-dimensional photonic crystals with a basisSep 30 2004We study propagation of light in square and hexagonal two-dimensional photonic crystals. We show, that slabs of these crystals focus light with subwavelength resolution. We propose a systematic way to increase this resolution, at an essentially fixed ... More
Extended T-process Regression ModelsMay 15 2017Gaussian process regression (GPR) model has been widely used to fit data when the regression function is unknown and its nice properties have been well established. In this article, we introduce an extended t-process regression (eTPR) model, a nonlinear ... More
Quantum Key Distribution with High Order Fibonacci-like Orbital Angular Momentum StatesDec 01 2016The coding space in quantum communication could be expanded to high-dimensional space by using orbital angular momentum (OAM) states of photons, as both the capacity of the channel and security are enhanced. Here we present a novel approach to realize ... 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
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
Topological quantum phase transitions and edge states in spin-orbital coupled Fermi gasesOct 31 2013Jun 08 2014We study the superconducting state in the presence of spin-orbital coupling and the Zeeman field. It is found that a phase transition from the Fulde-Ferrell-Larkin-Ovchinnikov state to the topological superconducting state occurs upon increasing the spin-orbital ... More
Predicting the solar maximum with the rising rateDec 24 2011The growth rate of solar activity in the early phase of a solar cycle has been known to be well correlated with the subsequent amplitude (solar maximum). It provides very useful information for a new solar cycle as its variation reflects the temporal ... More
Origin of Native Driving Force in Protein FoldingJul 27 1999Nov 13 1999We derive an expression with four adjustable parameters that reproduces well the 20x20 Miyazawa-Jernigan potential matrix extracted from known protein structures. The numerical values of the parameters can be approximately computed from the surface tension ... More
Novel $\mathbb{Z}_2$-topological metals and semimetalsMay 21 2015Dec 10 2015We report two theoretical discoveries for $\mathbb{Z}_2$-topological metals and semimetals. It is shown first that any dimensional $\mathbb{Z}_2$ Fermi surface is topologically equivalent to a Fermi point. Then the famous conventional no-go theorem, which ... More
Superluminal Behaviors of Electromagnetic Near-fieldsNov 14 2003May 16 2006Superluminal phenomena have been reported in many experiments of electromagnetic wave propagation, where the superluminal behaviors of evanescent waves are the most interesting ones with the important physical significances. Consider that evanescent waves ... More
Zero-viscosity limit of the Navier-Stokes equations with the Navier friction boundary conditionMay 25 2018In this paper, we consider the zero-viscosity limit of the Navier-Stokes equations in a half space with the Navier friction boundary condition $$ (\beta u^{\varepsilon}-\varepsilon^{\gamma}\partial_y u^{\varepsilon})|_{y=0}=0, $$ where $\beta$ is a constant ... More
RAE: The Rainforest Automation Energy Dataset for Smart Grid Meter Data AnalysisMay 14 2017Feb 12 2018Datasets are important for researchers to build models and test how well their machine learning algorithms perform. This paper presents the Rainforest Automation Energy (RAE) dataset to help smart grid researchers test their algorithms which make use ... More
Distributed Power Allocation and Channel Access Probability Assignment for Cognitive RadioFeb 04 2016In this paper, we present a framework for distributively optimizing the transmission strategies of secondary users in an ad hoc cognitive radio network. In particular, the proposed approach allows secondary users to set their transmit powers and channel ... More
Single qubit quantum secret sharing with improved securityMar 17 2007Mar 04 2011Analyzing carefully an experimentally feasible non-entangled single qubit quantum secret sharing protocol and its modified version [Phys. Rev. Lett. 95, 230505 (2005); ibid. 98, 028902 (2007)], it is found that both versions are insecure against coherent ... More
The relationship between two flavors of oblivious transfer at the quantum levelApr 22 2005Though all-or-nothing oblivious transfer and one-out-of-two oblivious transfer are equivalent in classical cryptography, we here show that due to the nature of quantum cryptography, a protocol built upon secure quantum all-or-nothing oblivious transfer ... More