Results for "T. Wu"

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The Electroweak Chiral Lagrangian and New Precision MeasurementsApr 08 1993A revised and complete list of the electroweak chiral lagrangian operators up to dimension-four is provided. The connection of these operators to the $S$, $T$ and $U$ parameters and the parameters describing the triple gauge boson vertices $WW\gamma$ ... More
On the Brezis-Nirenberg problem with nonhomogeneous Dirichlet boundary conditionsFeb 07 2015In this paper, we study the decomposition of Nehari manifold for the Br\'ezis-Nirenberg problem with nonhomogeneous Dirichlet boundary conditions. By using this result, the Lusternik-Schnirelman category and the minimax principle, we establish a multiple ... More
Generalised Inverse-Cowling Approximation for Polar $w$-mode Oscillations of Neutron StarsJul 12 2007Adopting the Lindblom-Detweiler formalism for polar oscillations of neutron stars, we study the $w$-mode oscillation and find that the Lagrangian change in pressure, measured by the physical quantity $X$, is negligibly small. Based on this observation, ... More
Gauge-invariant theory of optical response to THz pulses in s-wave and ($s$+$p$)-wave superconducting semiconductor quantum wellsMay 17 2017We investigate the optical response to the THz pulses in the s-wave and ($s$+$p$)-wave superconducting semiconductor quantum wells by using the gauge-invariant optical Bloch equations, in which the gauge structure in the superconductivity is explicitly ... More
Gapped triplet $p$-wave superconductivity in strong spin-orbit-coupled semiconductor quantum wells in proximity to $s$-wave superconductorFeb 18 2016Apr 27 2016We show that the {\it gapped} triplet superconductivity, i.e., a triplet superconductor with triplet order parameter, can be realized in strong spin-orbit-coupled quantum wells in proximity to $s$-wave superconductor. It is revealed that with the singlet ... More
Hot-electron effect in spin relaxation of electrically injected electrons in intrinsic GermaniumOct 06 2014Mar 27 2015The hot-electron effect in the spin relaxation of electrically injected electrons in intrinsic Germanium is investigated by the kinetic spin Bloch equations both analytically and numerically. It is shown that in the weak-electric-field regime with $E\lesssim ... More
Exploring the 3D architectures of deep material network in data-driven multiscale mechanicsJan 02 2019This paper extends the deep material network (DMN) proposed by Liu et al. (2018) to tackle general 3-dimensional (3D) problems with arbitrary material and geometric nonlinearities. The global framework of DMN for mechanistic data-driven multiscale material ... More
A novel superconducting-velocity--tunable quasiparticle state and spin relaxation in GaAs (100) quantum wells in proximity to $s$-wave superconductorJul 25 2016We present a novel quasiparticle state driven by a supercurrent in GaAs (100) quantum wells in proximity to an $s$-wave superconductor, which can be tuned by the superconducting velocity. Rich features such as the suppressed Cooper pairings, large quasiparticle ... More
Spin relaxation in ultracold spin-orbit coupled $^{40}$K gasSep 03 2013Sep 30 2013We report the anomalous Dyakonov-Perel' spin relaxation in ultracold spin-orbit coupled $^{40}$K gas when the coupling between $|9/2,9/2\ >$ and $|9/2,7/2\ >$ states (atcing as the effective Zeeman magnetic field) is much stronger than the spin-orbit ... More
Spin diffusion in ultracold spin-orbit coupled $^{40}$K gasApr 15 2015We investigate the steady-state spin diffusion for ultracold spin-orbit coupled $^{40}$K gas by the kinetic spin Bloch equation approach both analytically and numerically. Four configurations, i.e., the spin diffusions along two specific directions with ... More
Valley depolarization due to inter- and intra-valley electron-hole exchange interactions in monolayer MoS$_{2}$Dec 30 2013Mar 12 2014We investigate the valley depolarization due to the electron-hole exchange interaction in monolayer MoS$_{2}$. Both the long- and short-range parts of the intra- and inter-valley electron-hole exchange interactions are calculated. We find that both the ... More
Anomalous D'yakonov-Perel' spin relaxation in InAs (110) quantum wells under strong magnetic field: role of Hartree-Fock self-energyNov 01 2013We investigate the influence of the Hartree-Fock self-energy, acting as an effective magnetic field, on the anomalous D'yakonov-Perel' spin relaxation in InAs (110) quantum wells when the magnetic field in the Voigt configuration is much stronger than ... More
Optimal Detection For Sparse MixturesNov 09 2012Detection of sparse signals arises in a wide range of modern scientific studies. The focus so far has been mainly on Gaussian mixture models. In this paper, we consider the detection problem under a general sparse mixture model and obtain an explicit ... More
Exploring the 3D architectures of deep material network in data-driven multiscale mechanicsJan 02 2019Mar 05 2019This paper extends the deep material network (DMN) proposed by Liu et al. (2019) to tackle general 3-dimensional (3D) problems with arbitrary material and geometric nonlinearities. It discovers a new way of describing multiscale heterogeneous materials ... More
Novel valley depolarization dynamics and valley Hall effect of exciton in mono- and bilayer MoS$_2$Sep 15 2015We investigate the valley depolarization dynamics and valley Hall effect of exciton due to the electron-hole exchange interaction in mono- and bilayer MoS$_2$ by solving the kinetic spin Bloch equations. The effect of the exciton energy spectra by the ... More
Fourier Method for Approximating Eigenvalues of Indefinite Stekloff OperatorSep 07 2017Nov 16 2017We introduce an efficient method for computing the Stekloff eigenvalues associated with the Helmholtz equation. In general, this eigenvalue problem requires solving the Helmholtz equation with Dirichlet and/or Neumann boundary condition repeatedly. We ... More
Theory optical excitation spectra and depolarization dynamics in bilayer WS$_2$ from viewpoint of excimersJun 18 2014Jun 23 2014We investigate the optical excitation spectra and the photoluminescence depolarization dynamics in bilayer WS$_2$. A different understanding of the optical excitation spectra in the recent photoluminescence experimentby Zhu {\em et al.} [arXiv:1403.6224] ... More
Statistical and Computational Limits for Sparse Matrix DetectionJan 01 2018This paper investigates the fundamental limits for detecting a high-dimensional sparse matrix contaminated by white Gaussian noise from both the statistical and computational perspectives. We consider $p\times p$ matrices whose rows and columns are individually ... More
Determination of the forward slope in $p~p$ and $\bar p~p$ elastic scattering up to LHC energyNov 08 2010Mar 09 2011In the analysis of experimental data on $p p$ (or $\bar p p$) elastic differential cross section it is customary to define an average forward slope $b$ in the form $\exp{(-b|t|)}$, where $t$ is the momentum transfer. Taking as working example the results ... More
Colective Effects from Induced BehaviourAug 24 1999We present a solvable model for describing quantitatively situations where the individual behaviour of agents in a group "percolates" to collective behaviour of the group as a whole as a result of mutual influence between the agents.
Pion Form Factor in the $k_T$ Factorization FormalismApr 20 2004Jun 12 2004Based on the light-cone (LC) framework and the $k_T$ factorization formalism, the transverse momentum effects and the different helicity components' contributions to the pion form factor $F_{\pi}(Q^2)$ are recalculated. In particular, the contribution ... More
Optimal spatial-dynamic management to minimize the damages caused by aquatic invasive speciesSep 15 2018Invasive species have been recognized as a leading threat to biodiversity. In particular, lakes are especially affected by species invasions because they are closed systems sensitive to disruption. Accurately controlling the spread of invasive species ... More
Topological Charge of Lattice Abelian Gauge TheoryJan 26 2000Configuration space of abelian gauge theory on a periodic lattice becomes topologically disconnected by excising exceptional gauge field configurations. It is possible to define a U(1) bundle from the nonexceptional link variables by a smooth interpolation ... More
Photo-production of Bound States with Hidden CharmsOct 22 2012The photo-production of $J/\Psi$-$^3He$ bound state ($[^3He]_{J/\Psi}$) on a $^4He$ target has been investigated using the impulse approximation. The calculations have been performed using several $\gamma+N \rightarrow J/\Psi +N$ models based on the Pomeron-exchange ... More
Ergodicity and Mixing in Quantum DynamicsJan 04 2016Jul 27 2016After a brief historical review of ergodicity and mixing in dynamics, particularly in quantum dynamics, we introduce definitions of quantum ergodicity and mixing using the structure of the system's energy levels and spacings. Our definitions are consistent ... More
Anomalous Hall effect in semiconductor quantum wells in proximity to chiral p-wave superconductorsFeb 23 2018By using the gauge-invariant optical Bloch equation, we perform a microscopic kinetic investigation on the anomalous Hall effect in chiral p-wave superconducting states. Specifically, the intrinsic anomalous Hall conductivity in the absence of the magnetic ... More
Close-packed dimers on nonorientable surfacesOct 01 2001Feb 18 2002The problem of enumerating dimers on an M x N net embedded on non-orientable surfaces is considered. We solve both the Moebius strip and Klein bottle problems for all M and N with the aid of imaginary dimer weights. The use of imaginary weights simplifies ... More
Partition function zeroes of a self-dual Ising modelMay 22 1998May 26 1998We consider the Ising model on an $M\times N$ rectangular lattice with an asymmetric self-dual boundary condition, and derive a closed-form expression for its partition function. We show that zeroes of the partition function are given by the roots of ... More
Electronic, dynamical, and thermal properties of ultra-incompressible superhard rhenium diboride: A combined first-principles and neutron scattering studyAug 27 2007Aug 30 2007Rhenium diboride is a recently recognized ultra-incompressible superhard material. Here we report the electronic (e), phonon (p), e-p coupling and thermal properties of ReB$_2$ from first-principles density-functional theory (DFT) calculations and neutron ... More
COMPTEL Observation of the Flaring Quasar PKS0528+134Oct 08 1998With a direct demodulation method, we have reanalyzed the data from COMPTEL/CGRO observation of PKS0528+134 during the 1993 March flare in gamma-rays. Our results show that during the flare gamma-rays were detected at a level approximately 2.4-3.8 times ... More
Dynamic Security Analysis of Power Systems by a Sampling-Based AlgorithmNov 08 2018Dynamic security analysis is an important problem of power systems on ensuring safe operation and stable power supply even when certain faults occur. No matter such faults are caused by vulnerabilities of system components, physical attacks, or cyber-attacks ... More
Production of $J/Ψ$ on the nucleon and deuteron targetsMar 20 2013A coupled-channel model with $\pi N$, $\rho N$ and $J/\Psi N$ channels is developed to predict the $\pi + N \rightarrow J/\Psi + N $ cross sections. The $J/\Psi$-$N$ interaction is parameterized in a form related to what has been predicted by the effective ... More
Dimer statistics on the Möbius strip and the Klein bottleJun 10 1999Jun 14 1999Closed-form expressions are obtained for the generating function of close-packed dimers on a $2M \times 2N$ simple quartic lattice embedded on a M\"obius strip and a Klein bottle. Finite-size corrections are also analyzed and compared with those under ... More
Anomalous D'yakonov-Perel' spin relaxation in semiconductor quantum wells under strong magnetic field in Voigt configurationMar 20 2013May 22 2013We report an anomalous scaling of the D'yakonov-Perel' spin relaxation with the momentum relaxation in semiconductor quantum wells under a strong magnetic field in the Voigt configuration. We focus on the case that the external magnetic field is perpendicular ... More
Heteroskedastic PCA: Algorithm, Optimality, and ApplicationsOct 19 2018Principal component analysis (PCA) and singular value decomposition (SVD) are widely used in statistics, machine learning, and applied mathematics. It has been well studied in the case of homoskedastic noise, where the noise levels of the contamination ... More
Twenty Questions Games Always End With YesFeb 26 2010Huffman coding is often presented as the optimal solution to Twenty Questions. However, a caveat is that Twenty Questions games always end with a reply of "Yes," whereas Huffman codewords need not obey this constraint. We bring resolution to this issue, ... More
Sparse PCA: Optimal rates and adaptive estimationNov 06 2012Jan 07 2014Principal component analysis (PCA) is one of the most commonly used statistical procedures with a wide range of applications. This paper considers both minimax and adaptive estimation of the principal subspace in the high dimensional setting. Under mild ... More
Soluble kagome Ising model in a magnetic fieldSep 03 2004Oct 01 2004An Ising model on the kagome lattice with super-exchange interactions is solved exactly under the presence of a nonzero external magnetic field. The model generalizes the super-exchange model introduced by Fisher in 1960 and is analyzed in light of a ... More
Ising model on nonorientable surfaces: Exact solution for the Moebius strip and the Klein bottleJul 20 2000Closed-form expressions are obtained for the partition function of the Ising model on an M x N simple-quartic lattice embedded on a Moebius strip and a Klein bottle for finite M and N. The finite-size effects at criticality are analyzed and compared with ... More
Density of the Fisher zeroes for the Ising modelJan 27 2000The density of the Fisher zeroes, or zeroes of the partition function in the complex temperature plane, is determined for the Ising model in zero field as well as in a pure imaginary field i Pi/2. Results are given for the simple-quartic, triangular, ... More
On the duality relation for correlation functions of the Potts modelDec 03 1997Dec 08 1997We prove a recent conjecture on the duality relation for correlation functions of the Potts model for boundary spins of a planar lattice. Specifically, we deduce the explicit expression for the duality of the n-site correlation functions, and establish ... More
Evidence for Superhumps in the Radio Light Curve of Algol and a New Model for Magnetic Activity in Algol SystemsOct 11 2004Extensive radio data of two Algol systems and two RS CVn binaries were re-analyzed. We found evidence for a new periodicity that we interpret as a superhump in Algol, in which it may have been expected according to its semi-detached nature and low binary ... More
Production of Bound States with Hidden Charm at J-PARC and JLabDec 11 2012The cross sections of the production of bound states with hidden charm in reactions induced by pions and photons are presented. To facilitate the experimental efforts to determine the $J/\Psi$-N interactions, we present results for $J/\Psi$ production ... More
Transforming phylogenetic networks: Moving beyond tree spaceJan 08 2016Phylogenetic networks are a generalization of phylogenetic trees that are used to represent reticulate evolution. Unrooted phylogenetic networks form a special class of such networks, which naturally generalize unrooted phylogenetic trees. In this paper ... More
A deep material network for multiscale topology learning and accelerated nonlinear modeling of heterogeneous materialsJul 25 2018Oct 24 2018In this paper, a new data-driven multiscale material modeling method, which we refer to as deep material network, is developed based on mechanistic homogenization theory of representative volume element (RVE) and advanced machine learning techniques. ... More
Phylogenetic networks form partial treesSep 03 2007A contemporary and fundamental problem faced by many evolutionary biologists is how to puzzle together a collection $\mathcal P$ of partial trees (leaf-labelled trees whose leaves are bijectively labelled by species or, more generally, taxa, each supported ... More
Generalized Fibonacci numbers and dimer statisticsDec 13 2002Mar 21 2003We establish new product identities involving the $q$-analogue of the Fibonacci numbers. We show that the identities lead to alternate expressions of generating functions for close-packed dimers on non-orientable surfaces.
Correlation duality relations for the ($N_α, N_β$) modelDec 10 1997Dec 15 1997Duality relations for the correlation functions of $n$ sites on the boundary of a planar lattice are derived for the $(N_{\alpha}, N_{\beta})$ model of Domany and Riedel for $n=2,3$. Our result holds for arbitrary lattices which can have nonuniform interactions. ... More
Topological Obstruction in Block-spin TransformationsJun 06 2000Block-spin transformations from a fine lattice to a coarse one are shown to give rise to a one-to-one correspondence between the zero-modes of the Ginsparg-Wilson Dirac operators. The index is then preserved under the blocking process. Such a one-to-one ... More
Bound States in n Dimensions (Especially n = 1 and n = 2)Dec 04 2001We stress that in contradiction with what happens in space dimensions $n \geq 3$, there is no strict bound on the number of bound states with the same structure as the semi-classical estimate for large coupling constant and give, in two dimensions, examples ... More
Incoherent Pion Production in Neutrino - Deuteron ReactionsDec 07 2014Mar 05 2015Within the multiple scattering formulation, the incoherent pion production in neutrino-deuteron reactions at energies near the $\Delta(1232)$ resonance is investigated. The calculations include an impulse term and one-loop contributions from nucleon-nucleon ... More
Bound States in one and two Spatial DimensionsAug 06 2002In this paper we study the number of bound states for potentials in one and two spatial dimensions. We first show that in addition to the well-known fact that an arbitrarily weak attractive potential has a bound state, it is easy to construct examples ... More
Novel dynamical effects and glassy response in strongly correlated electronic systemMar 25 2007We find an unconventional nucleation of low temperature paramagnetic metal (PMM) phase with monoclinic structure from the matrix of high-temperature antiferromagnetic insulator (AFI) phase with tetragonal structure in strongly correlated electronic system ... More
Local and Non-local Shot Noise in Multiwalled Carbon NanotubesJun 18 2007We have investigated shot noise in multiterminal, diffusive multiwalled carbon nanotubes (MWNTs) at 4.2 K over the frequency f = 600 - 850 MHz. Quantitative comparison of our data to semiclassical theory, based on non-equilibrium distribution functions, ... More
Towards a guided atom interferometer based on a superconducting atom chipJun 11 2008We evaluate the realization of a novel geometry of a guided atom interferometer based on a high temperature superconducting microstructure. The interferometer type structure is obtained with a guiding potential realized by two current carrying superconducting ... More
Co-ordination between Rashba spin-orbital interaction and space charge effect and enhanced spin injection into semiconductorsApr 04 2003We consider the effect of the Rashba spin-orbital interaction and space charge in a ferromagnet-insulator/semiconductor/insulator-ferromagnet junction where the spin current is severely affected by the doping, band structure and charge screening in the ... More
Variation of the transition energies and oscillator strengths for the 3C and 3D lines of the Ne-like ions under plasma environmentApr 17 2019We present the results of a detailed theoretical study which meets the spatial and temporal criteria of the Debye-Hu\"ckel (DH) approximation on the variation of the transition energies as well as the oscillator strengths for the ${2p^53d\ ^1P_1\rightarrow2p^6\ ... More
Dynamics of ultra-intense circularly polarized solitons under inhomogeneous plasmasMar 18 2013The dynamics of the ultra-intense circularly polarized solitons under inhomogeneous plasmas are examined. The interaction is modeled by the Maxwell and relativistic hydrodynamic equations and is solved with fully implicit energy-conserving numerical scheme. ... More
The breather like penetration of the ultra-short linearly polarized laser into over-dense plasmasDec 03 2012Jan 10 2013Relativistic electromagnetic penetration behavior is reexamined in the relativistic transparency region. The interaction is modeled by the relativistic hydrodynamic equations coupled with the full system of Maxwell equations, which are solved by a fully ... More
Proximity Effects in Conical-Ferromagnet/Superconductor bilayersOct 12 2012We study various aspects of proximity effects in $F/S$ (Ferromagnet/Superconductor) bilayers, where $F$ has a spiral magnetic texture such as that found in Holmium, Erbium and other materials, and $S$ is a conventional s-wave superconductor. We numerically ... More
Proximity effects and triplet correlations in Ferromagnet/Ferromagnet/Superconductor nanostructuresJul 05 2012We report the results of a study of superconducting proximity effects in clean Ferromagnet/Ferromagnet/Superconductor (${\rm F_1F_2S}$) heterostructures, where the pairing state in S is a conventional singlet s-wave. We numerically find the self-consistent ... More
Folding and unfolding phylogenetic trees and networksJun 14 2015Phylogenetic networks are rooted, labelled directed acyclic graphs which are commonly used to represent reticulate evolution. There is a close relationship between phylogenetic networks and multi-labelled trees (MUL-trees). Indeed, any phylogenetic network ... More
Switching magnetoresistance in vertically interfaced Pr0.5Ca0.5MnO3 grown on ZnO nanowiresAug 03 2011The synthesis, morphology and magneto-transport properties of nanostructure-engineered charge-ordered Pr0.5Ca0.5MnO3 grown on ZnO nanowires are reported. The stability of the charge-ordering can be tuned, but more interestingly the sign of the magnetoresistance ... More
$τ$ polarization asymmetries in $B^+ \to τ^+ν_τγ$ and $B^+_c \to τ^+ν_τγ$May 02 1999We study the lepton polarization asymmetries in the radiative leptonic B decays of $B^+\to l^+\nu_{l}\gamma$ and $B^+_{c}\to l^+\nu_{l}\gamma$. We concentrate on the transverse component of the $\tau$ lepton asymmetries in the tau decay modes due to CP ... More
On the Stability Domain of Systems of Three Arbitrary ChargesDec 17 1998We present results on the stability of quantum systems consisting of a negative charge $-q_1$ with mass $m_{1}$ and two positive charges $q_2$ and $q_3$, with masses $m_{2}$ and $m_{3}$, respectively. We show that, for given masses $m_{i}$, each instability ... More
Asteroseismology of the $δ$ Scuti star HD 50844Jun 30 2016Aims. We aim to probe the internal structure and investigate more detailed information of the $\delta$ Scuti star HD 50844 with asteroseismology. Methods. We analyse the observed frequencies of the $\delta$ Scuti star HD 50844 obtained by Balona (2014), ... More
Do Linear Dispersions of Classical Waves Mean Dirac Cones?Feb 07 2012By using the \vec{k}\cdot\vec{p} method, we propose a first-principles theory to study the linear dispersions in phononic and photonic crystals. The theory reveals that only those linear dispersions created by doubly-degenerate states can be described ... More
Thermometry of Guided Molecular Beams from a Cryogenic Buffer-Gas CellMay 27 2016We present a comprehensive characterization of cold molecular beams from a cryogenic buffer-gas cell, providing an insight into the physics of buffer-gas cooling. Cold molecular beams are extracted from a cryogenic cell by electrostatic guiding, which ... More
Classification and Application of Triangular Quark Mass MatricesJul 27 1999Oct 04 1999The hierarchical structure in the quark masses and mixings allows its ten physical parameters to be most conveniently encoded in mass matrices of the upper triangular form. We classify these matrices in the hierarchical, minimal parameter basis where ... More
A Comparison Study of a Solar Active-Region Eruptive Filament and a Neighboring Non-Eruptive FilamentAug 20 2015Solar active region (AR) 11283 is a very magnetically complex region and it has produced many eruptions. However, there exists a non-eruptive filament in the plage region just next to an eruptive one in the AR, which gives us an opportunity to perform ... More
Nonlinear Force-Free Field Extrapolation of a Coronal Magnetic Flux Rope Supporting a Large-Scale Filament from Photospheric Vector MagnetogramMar 30 2014Solar filament are commonly thought to be supported in magnetic dips, in particular, of magnetic flux ropes (FRs). In this Letter, from the observed photospheric vector magnetogram, we implement a nonlinear force-free field (NLFFF) extrapolation of a ... More
Data Amplification: A Unified and Competitive Approach to Property EstimationMar 29 2019Estimating properties of discrete distributions is a fundamental problem in statistical learning. We design the first unified, linear-time, competitive, property estimator that for a wide class of properties and for all underlying distributions uses just ... More
Monte-Carlo approach to calculate the proton stopping in warm dense matter within particle-in-cell simulationsJul 10 2016A Monte-Carlo approach to proton stopping in warm dense matter is implemented into an existing particle-in-cell code. The model is based on multiple binary-collisions among electron-electron, electron-ion and ion-ion, taking into account contributions ... More
Study of the 3D Coronal Magnetic Field of Active Region 11117 Around the Time of a Confined Flare Using a Data-Driven CESE--MHD ModelSep 11 2012We apply a data-driven MHD model to investigate the three-dimensional (3D) magnetic field of NOAA active region (AR) 11117 around the time of a C-class confined flare occurred on 2010 October 25. The MHD model, based on the spacetime conservation-element ... More
Superconductivity at 43 K in Samarium-arsenide Oxides $SmFeAsO_{1-x}F_x$Mar 25 2008Mar 29 2008Since the discovery of high-transition temperature ($T_c$) superconductivity in layered copper oxides, extensive efforts have been devoted to explore the higher $T_c$ superconductivity. However, the $T_c$ higher than 40 K can be obtained only in the copper ... More
Timescale Resolved Spectroscopy of Cyg X-1Mar 24 2009We propose the timescale-resolved spectroscopy (TRS) as a new method to combine the timing and spectral study. TRS is based on the time domain power spectrum and reflects the variable amplitudes of spectral components on different timescales. We produce ... More
Ferroelectricity in Single Crystal InMnO3Mar 22 2013Single crystal synthesis, structure, electric polarization and heat capacity measurements on hexagonal InMnO3 show that this small R ion in the RMnO3 series is ferroelectric (space group P63cm). Structural analysis of this system reveals a high degree ... More
Structural Changes Related to the Magnetic Transitions in Hexagonal InMnO3Jun 17 2014Two magnetic ordering transitions are found in InMnO3, the paramagnetic to antiferromagnetic transition near ~118 K and a lower possible spin rotation transition near ~42 K. Multiple length scale structural measurements reveal enhanced local distortion ... More
Mutual Exclusion Statistics in Exactly Solvable Models in One and Higher Dimensions at Low TemperaturesApr 27 1995Jun 29 1996We study statistical characterization of the many-body states in exactly solvable models with internal degrees of freedom. The models under consideration include the isotropic and anisotropic Heisenberg spin chain, the Hubbard chain, and a model in higher ... More
Charge and Spin Currents in Ferromagnetic Josephson junctionsJun 17 2015We determine, using a self consistent method, the charge and spin currents in ballistic Josephson junctions consisting of ferromagnetic ($F$) layers sandwiched between superconducting ($S$) electrodes ($SFS$-type junctions). When there are two $F$ layers, ... More
Tunneling Conductance and Spin Transport in Clean Ferromagnet-Ferromagnet-Superconductor HeterostructuresAug 18 2014Sep 03 2014We present a transfer matrix approach that combines the Blonder-Tinkham-Klapwijk (BTK) formalism and self-consistent solutions to the Bogolibuov-de Gennes (BdG) equations and use it to study the tunneling conductance and spin transport in ferromagnet ... More
Reentrant superconductivity in conical-ferromagnet/superconductor nanostructuresNov 23 2011We study a bilayer consisting of an ordinary superconductor and a magnet with a spiral magnetic structure of the {\rm Ho} type. We use a self consistent solution of the Bogolioubov-de Gennes equations to evaluate the pair amplitude, the transition temperature, ... More
Ranking on Arbitrary Graphs: Rematch via Continuous LP with Monotone and Boundary Condition ConstraintsJul 10 2013Jul 11 2013Motivated by online advertisement and exchange settings, greedy randomized algorithms for the maximum matching problem have been studied, in which the algorithm makes (random) decisions that are essentially oblivious to the input graph. Any greedy algorithm ... More
GRB 060206: hints of precession of the central engine?Aug 08 2008Aims. The high-redshift (z = 4:048) gamma-ray burst GRB 060206 showed unusual behavior, with a significant rebrightening by a factor of ~ 4 at about 3000 s after the burst. We argue that this rebrightening implies that the central engine became active ... More
Maximal Neutrino Mixing from an Attractive Infrared Fixed PointAug 16 2001In the Standard Model (and MSSM), renormalization effects on neutrino mixing are generally very small and the attractive fixed points are at vanishing neutrino mixing. However for multi-higgs extensions of the Standard Model, renormalization effects on ... More
Seesaw model and its Lorentz group formulationMar 08 2000Jul 14 2000For two flavors, the seesaw matrix can be identified with a two dimensional representation of the Lorentz group. This analogy facilitates the computation of physical neutrino parameters, while giving an intuitive understanding of the results. It is found ... More
Mass Hierarchies and the Seesaw Neutrino MixingDec 15 1999Mar 20 2000We give a general analysis of neutrino mixing in the seesaw mechanism with three flavors. Assuming that the Dirac and u-quark mass matrices are similar, we establish simple relations between the neutrino parameters and individual Majorana masses. They ... More
Triangular Textures for Quark Mass MatricesJul 12 1999The hierarchical quark masses and small mixing angles are shown to lead to a simple triangular form for the U- and D-type quark mass matrices. In the basis where one of the matrices is diagonal, each matrix element of the other is, to a good approximation, ... More
The correlation timescale of the X-ray flux during the outbursts of soft X-ray transientsJul 03 2010Recent studies of black hole and neutron star low mass X-ray binaries (LMXBs) show a positive correlation between the X-ray flux at which the low/hard(LH)-to-high/soft(HS) state transition occurs and the peak flux of the following HS state. By analyzing ... More
Monte-Carlo approach to calculate the ionization of warm dense matter within particle-in-cell simulationsJul 10 2016Oct 11 2016A physical model based on a Monte-Carlo approach is proposed to calculate the ionization dynam- ics of warm dense matters (WDM) within particle-in-cell simulations, and where the impact (col- lision) ionization (CI), electron-ion recombination (RE) and ... More
Formation and Eruption of an Active Region Sigmoid: I. Study by Nonlinear Force-Free Field ModelingOct 30 2013We present a magnetic analysis of the formation and eruption of an active region (AR) sigmoid in AR 11283 from 2011 September 4 to 6. To follow the quasi-static evolution of the coronal magnetic field, we reconstruct a time sequence of static fields using ... More
Quantum-Classical Correspondence Principle for Work Distributions in a Chaotic SystemJan 20 2016May 18 2016We numerically study the work distributions in a chaotic system and examine the relationship between quantum work and classical work. Our numerical results suggest that there exists a correspondence principle between quantum and classical work distributions ... More
Numerical analysis on mixing processes for transcritical real-fluid simulationsDec 06 2017The accurate and robust simulation of transcritical real-fluid flows is crucial for many engineering applications. Diffused interface methods are frequently employed and several numerical schemes have been developed for simulating transcritical flows. ... More
Giant isotope effect and spin state transition induced by oxygen isotope exchange in ($Pr_{1-x}Sm_x)_{0.7}Ca_{0.3}CoO_3$Mar 28 2006Apr 30 2006We systematically investigate effect of oxygen isotope in $(Pr_{1-x}Sm_x)_{0.7}Ca_{0.3}CoO_3$ which shows a crossover with x from ferromagnetic metal to the insulator with spin-state transition. A striking feature is that effect of oxygen isotope on the ... More
Magnetotransport properties in purple bronze Li$_{0.9}$Mo$_6$O$_{17}$ Single CrystalJun 21 2009We have measured resistivity along the a, b and c axes of Li$_{0.9}$Mo$_6$O$_{17}$ single crystal. The anisotropy $\rho$$_c$ / $\rho$$_a$ and $\rho$$_c$ / $\rho$$_b$ is given, confirming the quasi-one-dimensionality of the compound. The sharp decrease ... More
Crowdsourcing with Tullock contests: A new perspectiveJan 05 2017Incentive mechanisms for crowdsourcing have been extensively studied under the framework of all-pay auctions. Along a distinct line, this paper proposes to use Tullock contests as an alternative tool to design incentive mechanisms for crowdsourcing. We ... More
Exchange in multi-defect semiconductor clusters: assessment of `control-qubit' architecturesNov 01 2007We present a variational method to calculate the exchange interactions among donor clusters in a semiconductor. Such clusters are candidates for a so-called control-qubit architecture for quantum information, where the effective exchange coupling between ... More
High-frequency behavior of w-mode pulsations of compact starsJan 01 2011We study the asymptotic behavior of the quasi-normal modes (QNMs) of w-mode pulsations of compact stars in the high-frequency regime. We observe that both the axial and polar w-mode QNMs attain similar asymptotic behaviors in spite of the fact that they ... More
RF Cavities For The Muon and Neutrino Factory Collaboration StudyAug 18 2000A multi-laboratory collaboration is studying the feasibility of building a muon collider, the first phase of which maybe a neutrino factory. The phase space occupied by the muons is very large and needs to be cooled several orders of magnitude for either ... More
The Deformation Effect on the Electronic Structure of the Graphite Nanoribbon ArraysOct 25 2008We have performed a first-principles study on the deformation effect of the electronic structures of graphite nanoribbon arrays with zigzag edges on both sides, and the edge atoms are terminated with hydrogen atoms. A uniaxial strain is considered to ... More