Results for "Ling Lu"

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Topological one-way fiber of second Chern numberNov 07 2016Optical fiber is a ubiquitous and indispensable component in communications, sensing, biomedicine and many other lightwave technologies and applications. Here we propose topological one-way fibers to remove two fundamental mechanisms that limit fiber ... More
Enhanced spin injection efficiency in a four-terminal double quantum dot systemDec 02 2009Within the scheme of quantum rate equations, we investigate the spin-resolved transport through a double quantum dot system with four ferromagnetic terminals. It is found that the injection efficiency of spin-polarized electrons can be significantly improved ... More
Topological Phononic Crystals with One-Way Elastic Edge WavesApr 04 2015We report a new type of phononic crystals with topologically non-trivial bandgaps for both longitudinal and transverse polarizations, resulting in protected one-way elastic edge waves. In our design, gyroscopic inertial effects are used to break the time-reversal ... More
A Mathematical Theory of Optimal Milestoning (with a Detour via Exact Milestoning)Sep 08 2016Milestoning is a computational procedure that reduces the dynamics of complex systems to memoryless jumps between intermediates, or milestones, and only retains some information about the probability of these jumps and the time lags between them. Here ... More
High-dimensional robust precision matrix estimation: Cellwise corruption under $ε$-contaminationSep 24 2015We analyze the statistical consistency of robust estimators for precision matrices in high dimensions. We focus on a contamination mechanism acting cellwise on the data matrix. The estimators we analyze are formed by plugging appropriately chosen robust ... More
Photon scattering from strongly driven atomic ensemblesAug 23 2011The second order correlation function for light emitted from a strongly and near-resonantly driven dilute cloud of atoms is discussed. Because of the strong driving, the fluorescence spectrum separates into distinct peaks, for which the spectral properties ... More
Comments on "Unusual Thermoelectric Behavior Indicating a Hopping to Bandlike Transport Transition in Pentacene"Nov 19 2012Dec 03 2012W. Chr. Germs, K. Guo, R. A. J. Janssen, and M. Kemerink [1] recently measured the temperature and concentration dependent seebeck coefficient in organic thin film transistor and found the seebeck coefficient increases with carrier concentration (corresponding ... More
Universal Einstein Relation Model in Disordered Organic Semiconductors under Quasi-equilibriumOct 10 2013It is still under debate whether the classical Einstein relation in disordered organic semiconductors is valid. We investigated Einstein relation in disordered organic semiconductors theoretically. The results show that, the classic Einstein relation ... More
Physical Origin of Nonlinear transport in organic semiconductor at high carrier densitiesOct 10 2013The charge transport in some organic semiconductors demonstrates nonlinear properties and further universal power-law scaling with both bias and temperature. The physical origin of this behavior is investigated here using variable range hopping theory. ... More
Weyl points and line nodes in gapless gyroid photonic crystalsJul 02 2012Weyl points and line nodes are three-dimensional linear point- and line-degeneracies between two bands. In contrast to Dirac points, which are their two-dimensional analogues, Weyl points are stable in the momentum space and the associated surface states ... More
Comment on "Linear Scaling of the Exciton Binding Energy versus the Band Gap of Two-Dimensional Materials"Sep 13 2016In a recent letter [J. -H. Choi et al. Phys. Rev. Lett. 115, 066403 (2015)], a universal linear relation between the binding energy Eb of exciton and the band gap Eg is found in different quasi-2D semiconductors. However, when one extrapolates the straight ... More
Extremely terahertz electric-field enhancement in a high-Q photonic crystal slab cavity with nanoholesJul 25 2018A one-dimensional photonic-crystal (PC) cavity with nanoholes is proposed for extremely enhancing the THz electric fields by utilizing the electromagnetic (EM) boundary conditions, where both slot effect (for the perpendicular component of the electric ... More
DIAG-NRE: A Deep Pattern Diagnosis Framework for Distant Supervision Neural Relation ExtractionNov 06 2018Modern neural network models have achieved the state-of-the-art performance on relation extraction (RE) tasks. Although distant supervision (DS) can automatically generate training labels for RE, the effectiveness of DS highly depends on datasets and ... More
Extremely local electric field enhancement and light confinement in dielectric waveguideOct 09 2013The extremely local electric field enhancement and light confinement is demonstrated in dielectric waveguide with corner and gap geometry. The numerical results reveal the local electric field enhancement in the vicinity of the apex of fan-shaped waveguide. ... More
Dielectric Bow-tie NanocavityOct 09 2013We propose a novel dielectric bow-tie nanocavity consisting of two tip-to-tip opposite triangle semiconductor nanowires, whose end faces are coated by silver nanofilms. Based on the advantages of the dielectric slot and tip structures, and the high reflectivity ... More
Direct Probe of Topological Order for Cold AtomsJul 04 2014Nov 17 2014Cold-atom experiments in optical lattices offer a versatile platform to realize various topological quantum phases. A key challenge in those experiments is to unambiguously probe the topological order. We propose a method to directly measure the characteristic ... More
Deterministic Sequences for Compressive MIMO Channel EstimationNov 02 2013This paper considers the problem of pilot design for compressive multiple-input multiple-output (MIMO) channel estimation. In particular, we are interested in estimating the channels for multiple transmitters simultaneously when the pilot sequences are ... More
Charge carrier relaxation model in hopping systemMar 18 2013The relaxation phenomena of charge carriers in hopping system have been demonstrated and investigated theoretically. An analytical model describing the charge carrier relaxation is proposed based on the hopping transport theory. The relation between the ... More
A 2D based Partition Strategy for Solving Ranking under Team Context (RTP)Apr 14 2014In this paper, we propose a 2D based partition method for solving the problem of Ranking under Team Context(RTC) on datasets without a priori. We first map the data into 2D space using its minimum and maximum value among all dimensions. Then we construct ... More
Object Selection under Team ContextDec 18 2013Apr 14 2014Context-aware database has drawn increasing attention from both industry and academia recently by taking users' current situation and environment into consideration. However, most of the literature focus on individual context, overlooking the team users. ... More
Global Adaptive Routing Algorithm Without Additional Congestion Propagation NetworkAug 02 2012Adaptive routing algorithm has been employed in multichip interconnection networks in order to improve network performance. Does a algorithm use local or global network state? This is the key question in adaptive routing. In many traffic patterns, the ... More
Probe of Three-Dimensional Chiral Topological Insulators in an Optical LatticeFeb 05 2014Jul 17 2014We propose a feasible experimental scheme to realize a three-dimensional chiral topological insulator with cold fermionic atoms in an optical lattice, which is characterized by an integer topological invariant distinct from the conventional $Z_2$ topological ... More
Anomalous Chiral Modes and Topological Invariant of Floquet DefectsDec 01 2016Backscattering-immune chiral modes arise along certain line defect in three-dimensional materials. We study Floquet chiral modes along Floquet defects, namely, the topological defects come entirely from spatial modulations of periodic driving. We define ... More
An experimental proposal to observe non-abelian statistics of Majorana-Shockley fermions in an optical latticeAug 25 2014We propose an experimental scheme to observe non-abelian statistics with cold atoms in a two dimensional optical lattice. We show that the Majorana-Schockley modes associated with line defects obey non-abelian statistics and can be created, braided, and ... More
Experimental observation of Weyl pointsFeb 11 2015In 1929, Hermann Weyl derived the massless solutions from the Dirac equation - the relativistic wave equation for electrons. Neutrinos were thought, for decades, to be Weyl fermions until the discovery of the neutrino mass. Moreover, it has been suggested ... More
Self-Learning to Detect and Segment Cysts in Lung CT Images without Manual AnnotationJan 25 2018Image segmentation is a fundamental problem in medical image analysis. In recent years, deep neural networks achieve impressive performances on many medical image segmentation tasks by supervised learning on large manually annotated data. However, expert ... More
Weyl points in three-dimensional optical lattices: synthetic magnetic monopoles in momentum spaceDec 24 2014We show that Hamiltonians with Weyl points can be realized for ultracold atoms using laser-assisted tunneling in three-dimensional optical lattices. Weyl points are synthetic magnetic monopoles that exhibit a robust, three-dimensional linear dispersion. ... More
Thermodynamics of $f(R)$ Gravity with Disformal TransformationFeb 13 2019We study thermodynamics in $f(R)$ gravity with the disformal transformation. The transformation applied to the matter Lagrangian has the form of $\g_{\m\n} = A(\phi,X)g_{\m\n} + B(\phi,X)\pa_\m\f\pa_\n\f$ with the assumption of the Minkowski matter metric ... More
Radiative Corrections to the Z-b-(anti-b) and Z-tau-(anti-tau) Vertices in a Realistic One-Family Extended Technicolor ModelJun 30 1995In a realistic effective one-family extended technicolor(ETC) model without exact custodial symmetry, we calculate the one-loop corrections to the Z-b-(anti-b) and Z-tau-(anti-tau)vertices from the sideways and diagonal ETC bosons exchange. The result ... More
Convolutional Invasion and Expansion Networks for Tumor Growth PredictionJan 25 2018Tumor growth is associated with cell invasion and mass-effect, which are traditionally formulated by mathematical models, namely reaction-diffusion equations and biomechanics. Such models can be personalized based on clinical measurements to build the ... More
Neural Network-Based Abstract Generation for Opinions and ArgumentsJun 09 2016We study the problem of generating abstractive summaries for opinionated text. We propose an attention-based neural network model that is able to absorb information from multiple text units to construct informative, concise, and fluent summaries. An importance-based ... More
DeepPap: Deep Convolutional Networks for Cervical Cell ClassificationJan 25 2018Automation-assisted cervical screening via Pap smear or liquid-based cytology (LBC) is a highly effective cell imaging based cancer detection tool, where cells are partitioned into "abnormal" and "normal" categories. However, the success of most traditional ... More
Topological nature of bound states in the radiation continuumAug 01 2014Bound states in the continuum (BICs) are unusual solutions of wave equations describing light or matter: they are discrete and spatially bounded, but exist at the same energy as a continuum of states which propagate to infinity. Until recently, BICs were ... More
Design and implementation of the NaI (Tl)CsI (Na) detectors output signal generatorMay 16 2013We designed and implemented a signal generator that can simulate the output of the NaI (Tl)CsI (Na) detectors pre amplifier onboard the Hard X ray Modulation Telescope (HXMT). Using the development of FPGA (Field Programmable Gate Array) with VHDL language ... More
Guiding Robust Valley-dependent Edge States by Surface Acoustic WavesOct 08 2018Recently, the concept of valley pseudospin, labeling quantum states of energy extrema in momentum space, has attracted enormous attention because of its potential as a new type of information carrier. Here, we present surface acoustic wave (SAW) waveguides, ... More
Experimental Identification of Non-Abelian Topological Orders on a Quantum SimulatorAug 24 2016Feb 01 2017Topological orders can be used as media for topological quantum computing --- a promising quantum computation model due to its invulnerability against local errors. Conversely, a quantum simulator, often regarded as a quantum computing device for special ... More
A study of raining influence on the environmental radiation background spectra with HXMT/HENov 25 2016Full functional and performance tests were performed many times before the Hard X-ray Modulation Telescope (HXMT) launch. During one of the tests, the count rate curves of the 18 High Energy Detectors (HED) have been found increased consistently within ... More
Do Intermediate-Mass Black Holes Exist in Globular Clusters?Aug 13 2013The existence of intermediate-mass black holes (IMBHs) in globular clusters (GCs) remains a crucial problem. Searching IMBHs in GCs reveals a discrepancy between radio observations and dynamical modelings: the upper mass limits constrained by radio observations ... More
Topological magnetoplasmonFeb 01 2016Mar 27 2016Classical wave fields are real-valued, ensuring the modes at opposite frequencies and momenta to be inherently identical. Such a "particle-hole" symmetry opens up new possibilities for topological phenomena in classical systems. Here we show that the ... More
Fe-doping induced superconductivity in charge-density-wave system 1T-TaS2Sep 19 2011Sep 12 2012We report the interplay between charge-density-wave (CDW) and superconductivity of 1$T$-Fe$_{x}$Ta$_{1-x}$S$_{2}$ ($0\leq x \leq 0.05$) single crystals. The CDW order is gradually suppressed by Fe-doping, accompanied by the disappearance of pseudogap/Mott-gap ... More
Far-Field Tunable Nano-focusing Based on Metallic Slits Surrounded with Nonlinear-Variant Widths and Linear-Variant Depths of Circular Dielectric GratingJan 11 2013In this work, we design a new tunable nanofocusing lens by the linear-variant depths and nonlinear-variant widths of circular grating for far field practical applications. The constructively interference of cylindrical surface plasmon launched by the ... More
Topological magnetoplasmonFeb 01 2016Dec 07 2016Classical wave fields are real-valued, ensuring the wave states at opposite frequencies and momenta to be inherently identical. Such a particle-hole symmetry can open up new possibilities for topological phenomena in classical systems. Here we show that ... More
Doubly and triply coupled nanowire antennasMar 20 2012Nanoantenna is one of the most important optical components for light harvesting. In this study, we show experimental evidence of interactions between coupled nanowires by comparing the fluorescence properties of quantum dots on both non-coupled (single) ... More
Polar Codes and Polar Lattices for Independent Fading ChannelsJan 19 2016Feb 05 2016In this paper, we design polar codes and polar lattices for i.i.d. fading channels when the channel state information is only available to the receiver. For the binary input case, we propose a new design of polar codes through single-stage polarization ... More
Topological PhotonicsAug 28 2014Oct 31 2014Topology is revolutionizing photonics, bringing with it new theoretical discoveries and a wealth of potential applications. This field was inspired by the discovery of topological insulators, in which interfacial electrons transport without dissipation ... More
Fault Tolerant Quantum Random Number Generator Certified by Majorana FermionsMar 26 2013Braiding of Majorana fermions gives accurate topological quantum operations that are intrinsically robust to noise and imperfection, providing a natural method to realize fault-tolerant quantum information processing. Unfortunately, it is known that braiding ... More
Validity of Transport Energy in Disordered Organic SemiconductorsNov 18 2012Nov 20 2012A systematic study of the transport energy in disordered organic semiconductors based on variable range hopping theory has been presented here. The temperature, electric field, material disorder and carrier concentration dependent transport energy is ... More
Jitter analysis of a superconducting nanowire single photon detectorAug 04 2013Jitter is one of the key parameters for a superconducting nanowire single photon detector (SNSPD). Using an optimized time-correlated single photon counting system for jitter measurement, we extensively studied the dependence of system jitter on the bias ... More
Multiplicity-Free Representations of Divergence-Free Lie AlgebrasDec 16 2010Divergence-free Lie algebras (also known as the special Lie algebras of Cartan type) are Lie algebras of volume-preserving transformation groups. They are simple in generic case. Dokovic and Zhao found a certain graded generalization of them. In this ... More
A Function obstruction to the Existence of Complex StructuresJan 05 2019We construct a function for almost-complex Riemannian manifolds. Non-vanishing of the function for the almost-complex structure implies the almost-complex structure is not integrable. Therefore the constructed function is an obstruction for the existence ... More
Some Asymptotic Behavior of the first Eigenvalue along the Ricci FlowOct 23 2007We study some asymptotic behavior of the first nonzero eigenvalue of the Lalacian along the normalized Ricci flow and give a direct short proof for an asymptotic upper limit estimate.
Orthogonal symmetric Toeplitz matrices for compressed sensing: Statistical isometry propertyDec 29 2010Oct 24 2012Recently, the statistical restricted isometry property (RIP) has been formulated to analyze the performance of deterministic sampling matrices for compressed sensing. In this paper, we propose the usage of orthogonal symmetric Toeplitz matrices (OSTM) ... More
Robust pinning of magnetic moments in pyrochlore iridatesMay 02 2017Aug 30 2017Pyrochlore iridates A2Ir2O7 (A = rare earth elements, Y or Bi) hold great promise for realizing novel electronic and magnetic states owing to the interplay of spin-orbit coupling, electron correlation and geometrical frustration. A prominent example is ... More
Experimental Test of Generalized Hardy's ParadoxAug 15 2018Since the pillars of quantum theory were established, it was already noted that quantum physics may allow certain correlations defying any local realistic picture of nature, as first recognized by Einstein, Podolsky and Rosen. These quantum correlations, ... More
A Broadband DLCZ Quantum Memory in Room-Temperature AtomsApr 20 2017Sep 24 2018Quantum memory capable of stopping flying photons and storing their quantum coherence is essential for scalable quantum technologies. A room-temperature broadband quantum memory will enable the implementation of large-scale quantum systems for real-life ... More
Topological PhotonicsFeb 12 2018Topological photonics is a rapidly-emerging field of research in which geometrical and topological ideas are exploited to design and control the behavior of light. Drawing inspiration from the discovery of the quantum Hall effects and topological insulators ... More
The first Dirichlet Eigenvalue of a Compact Manifold and the Yang ConjectureJul 08 2004Dec 08 2004We give a new estimate on the lower bound of the first Dirichlet eigenvalue of a compact Riemannian manifold with negative lower bound of Ricci curvature and provide a solution for a conjecture of H. C. Yang.
The Non-existence of Complex Sphere $S^n$ ($n>2$)Jan 01 2019Jan 08 2019We show the non-existence of complex structure on sphere with the standard round metric, of any dimension other than two, in particular, on $S^6$.
Hypergeometric evaluation identities and supercongruencesDec 01 2009Dec 16 2010In this article, we provide an application of hypergeometric evaluation identities, including a strange valuation of Gosper, to prove several supercongruences related to special valuations of truncated hypergeometric series. In particular, we prove a ... More
Curvature flow of complete hypersurfaces in hyperbolic spaceOct 13 2011In this paper we continue our study of finding the curvature flow of complete hypersurfaces in hyperbolic space with a prescribed asymptotic boundary at infinity. Our main results are proved by deriving a priori global gradient estimates and C^2 estimates. ... More
Curvature flow of complete convex hypersurfaces in hyperbolic spaceJun 22 2011We investigate the existence, convergence and uniqueness of modified general curvature flow of convex hypersurfaces in hyperbolic space with a prescribed asymptotic boundary.
Some Representations of Nongraded Divergence-Free Lie AlgebrasJan 15 2012Divergence-free Lie algebras are originated from the Lie algebras of volume-preserving transformation groups. Xu constructed a certain nongraded generalization, which may not contain any toral Cartan subalgebra. In this paper, we give a complete classification ... More
Superconductivity at 52 K in iron-based F-doped layered quaternary compound Pr[O1-xFx]FeAsMar 29 2008Since the discovery of copper oxide superconductor in 1986 [1], extensive efforts have been devoted to the search of new high-Tc superconducting materials, especially high-Tc systems other than cuprates. The recently discovered quaternary superconductor ... More
Effect of Notch Structure on Magnetic Domain Movement in Planar NanowiresNov 23 2017We present the direct observation of magnetic domain motion in permalloy nanowires with notches using a wide-field Kerr microscopy technique. The domain wall motion can be modulated by the size and shape of the notch structure in the nanowires. It is ... More
Binary matrices of optimal autocorrelations as alignment marksAug 29 2014We define a new class of binary matrices by maximizing the peak-sidelobe distances in the aperiodic autocorrelations. These matrices can be used as robust position marks for in-plane spatial alignment. The optimal square matrices of dimensions up to 7 ... More
Spawning rings of exceptional points out of Dirac conesApr 03 2015The Dirac cone underlies many unique electronic properties of graphene and topological insulators, and its band structure--two conical bands touching at a single point--has also been realized for photons in waveguide arrays, atoms in optical lattices, ... More
Defect Engineering for Modulating the Trap States in Two-dimensional PhotoconductorAug 18 2018Defect induced trap states are essential in determining the performance of semiconductor photodetectors. The de-trap time of carriers from a deep trap could be prolonged by several orders of magnitude as compared to shallow trap, resulting in additional ... More
Characterization of superconducting nanowire single-photon detector with artificial constrictionsJun 09 2014Statistical studies on the performance of different superconducting nanowire single-photon detectors (SNSPDs) on one chip suggested that random constrictions existed in the nanowire that were barely registered by scanning electron microscopy. With the ... More
Index computations on FJRW theoryOct 23 2012Nov 29 2012We compute the index of the real Cauchy-Riemann operator defined in FJRW theory in case of the smooth metric. For the cylindrical metric, we study the relation between the index of the linearized operator of Witten map and weights in weighted Sobolev ... More
Finite index subgroups of the modular group and their modular formsJul 23 2007Classically, congruence subgroups of the modular group, which can be described by congruence relations, play important roles in group theory and modular forms. In reality, the majority of finite index subgroups of the modular group are noncongruence. ... More
Testing for change points in time series models and limiting theorems for NED sequencesAug 17 2007This paper first establishes a strong law of large numbers and a strong invariance principle for forward and backward sums of near-epoch dependent sequences. Using these limiting theorems, we develop a general asymptotic theory on the Wald test for change ... More
An $S_3$-symmetry of the Jacobi Identity for Intertwining Operator AlgebrasJul 18 2015Jul 31 2015We prove an $S_{3}$-symmetry of the Jacobi identity for intertwining operator algebras. Since this Jacobi identity involves the braiding and fusing isomorphisms satisfying the genus-zero Moore-Seiberg equations, our proof uses not only the basic properties ... More
A Lower Bound of the First Eigenvalue of a Closed Manifold with Negative Lower Bound of the Ricci CurvatureJun 28 2004Dec 08 2004Along the line of the Yang Conjecture, we give a new estimate on the lower bound of the first non-zero eigenvalue of a closed Riemannian manifold with negative lower bound of Ricci curvature in terms of the in-diameter and the lower bound of Ricci curvature. ... More
On Axiomatic Approaches to Intertwining Operator AlgebrasMar 22 2015Jul 31 2015We study intertwining operator algebras introduced and constructed by Huang. In the case that the intertwining operator algebras involve intertwining operators among irreducible modules for their vertex operator subalgebras, a number of results on intertwining ... More
A Class of Monotonic Quantities along the Ricci FlowOct 23 2007Oct 24 2007We construct a class of monotonic quantities along the normalized Ricci flow on closed n-dimensional manifolds.
Convolutional Compressed Sensing Using Deterministic SequencesOct 28 2012In this paper, a new class of circulant matrices built from deterministic sequences is proposed for convolution-based compressed sensing (CS). In contrast to random convolution, the coefficients of the underlying filter are given by the discrete Fourier ... More
Study on the unfolding algorithm for D-T neutron energy spectra measurement using recoil proton methodOct 16 2014A proton recoil method for measuring D-T neutron energy spectra using polyethylene film and Si (Au) surface barrier detector was presented. An iteration algorithm for unfolding the recoil proton energy spectrum to the neutron energy spectrum was investigated. ... More
Probing topological protection using a designer surface plasmon structureApr 29 2015Jan 17 2016Topological photonic states, inspired by robust chiral edge states in topological insulators, have recently been demonstrated in a few photonic systems, including an array of coupled on-chip ring resonators at communication wavelengths. However, the intrinsic ... More
A q-analogue of Wolstenholme's harmonic series congruenceJul 25 2005We establish a q-analogue of Wolstenholme's harmonic series congruence.
Estimates on the Lower Bound of the First GapApr 22 2004Jan 04 2005We give a new lower bound for the first gap $\lambda_2 - \lambda_1$ of the Dirichlet eigenvalues of the Schr{\"o}dinger operator on a bounded convex domain $\Omega$ in R$^n$ or S$^n$ and greatly sharpens the previous estimates. The new bound is explicit ... More
A Lower Bound of the First Dirichlet Eigenvalue of a Compact Manifold with Positive Ricci CurvatureJun 07 2004Dec 08 2004We give a new estimate on the lower bound for the first Dirichlet eigenvalue for a compact manifold with positive Ricci curvature in terms of the in-diameter and the lower bound of the Ricci curvature. The result improves the previous estimates.
A Comparison Theorem and A Sharp Bound via the Ricci FlowOct 13 2007Dec 15 2009We prove a comparison theorem for the compact surfaces with negative Euler characteristic via the Ricci flow.
A structure theorem of Dirac-harmonic maps between spheresJun 24 2008For an arbitrary Dirac-harmonic map $(\phi,\psi)$ between compact oriented Riemannian surfaces, we shall study the zeros of $|\psi|$. With the aid of Bochner-type formulas, we explore the relationship between the order of the zeros of $|\psi|$ and the ... More
Extracting Wyner's Common Information Using Polar Codes and Polar LatticesMar 17 2016Oct 25 2016Explicit constructions of polar codes and polar lattices for both lossless and lossy Gray-Wyner problems are studied. Polar codes are employed to extract Wyner's common information of doubly symmetric binary source; polar lattices are then extended to ... More
Cavity-Mediated Strong Matter Wave Bistability in a Spin-1 CondensateAug 29 2009We study matter wave bistability in a spin-1 Bose-Einstein condensate dispersively coupled to a unidirectional ring cavity. A unique feature is that the population exchange among different modes of matter fields are accomplished via the spin-exchange ... More
Systematic Construction of tight-binding Hamiltonians for Topological Insulators and SuperconductorsNov 05 2013Feb 21 2014A remarkable discovery in recent years is that there exist various kinds of topological insulators and superconductors characterized by a periodic table according to the system symmetry and dimensionality. To physically realize these peculiar phases and ... More
Modulated Unit-Norm Tight Frames for Compressed SensingNov 27 2014In this paper, we propose a compressed sensing (CS) framework that consists of three parts: a unit-norm tight frame (UTF), a random diagonal matrix and a column-wise orthonormal matrix. We prove that this structure satisfies the restricted isometry property ... More
Method of Divide-and-Combine in Regularised Generalised Linear Models for Big DataNov 18 2016When a data set is too big to be analysed entirely once by a single computer, the strategy of divide-and-combine has been the method of choice to overcome the computational hurdle due to its scalability. Although random data partition has been widely ... More
Topological semimetals with Riemann surface statesDec 04 2015Riemann surfaces are geometric constructions in complex analysis that may represent multi-valued holomorphic functions using multiple sheets of the complex plane. We show that the energy dispersion of surface states in topological semimetals can be represented ... More
Extracting Wyner's Common Randomness Using Polar CodesMar 17 2016May 13 2016Explicit construction of polar codes for the Gray-Wyner network is studied. We show that Wyner's common information plays an essential role in constructing polar codes for both lossless and lossy Gray-Wyner coding problems. For discrete joint sources, ... More
Hamiltonian tomography for quantum many-body systems with arbitrary couplingsMay 04 2015Oct 04 2015Characterization of qubit couplings in many-body quantum systems is essential for benchmarking quantum computation and simulation. We propose a tomographic measurement scheme to determine all the coupling terms in a general many-body Hamiltonian with ... More
Superconductivity at 55 K in iron-based F-doped layered quaternary compound Sm[O1-xFx]FeAsApr 13 2008May 15 2008Here we report the superconductivity in the iron-based oxyarsenide Sm[O1-xFx]FeAs, with the onset resistivity transition temperature at 55.0 K and Meissner transition at 54.6 K. This compound has the same crystal structure as LaOFeAs with shrunk crystal ... More
Superconductivity at 53.5 K in GdFeAsO1-deltaApr 23 2008May 21 2008Here we report the fabrication and superconductivity of the iron-based arsenic-oxide GdFeAsO1-delta compound with oxygen-deficiency, which has an onset resistivity transition temperature at 53.5 K. This material has a same crystal structure as the newly ... More
Superconductivity and Phase Diagram in the Iron-based Arsenic-oxides ReFeAsO1-delta (Re = rare earth metal) without F-DopingApr 16 2008May 08 2008Here we report a new class of superconductors prepared by high pressure synthesis in the quaternary family ReFeAsO1-delta (Re = Sm, Nd, Pr, Ce, La) without fluorine doping. The onset superconducting critical temperature (Tc) in these compounds increases ... More
Superconductivity in iron-based F-doped layered quaternary compound Nd[O1-xFx]FeAsMar 31 2008May 21 2008The recently discovered quaternary arsenide oxide superconductor La[O1-xFx]FeAs with the superconducting critical transition temperature (Tc) of 26 K [1], has been quickly expanded to another high-Tc superconducting system beyond copper oxides by the ... More
Novel high pressure structures and superconductivity of niobium disulfideJan 15 2014We have investigated the pressure-induced phase transition and superconducting properties of niobium disulfide (NbS$_2$) based on the density functional theory. The structures of NbS$_2$ at pressures from 0 to 200 GPa were predicted using the multi-algorithm ... More
High-Tc Superconductivity in some Heavy Rare-earth Iron-arsenide REFeAsO1-delta(RE = Ho, Y, Dy and Tb) CompoundsSep 22 2008New iron-arsenide superconductors of REFeAsO1-delta (RE = Ho, Y, Dy and Tb) were successfully synthesized by a high pressure synthesizing method with a special rapid quenching process, with the onset superconducting critical temperatures at 50.3 K, 46.5 ... More
Superconductivity enhancement in the S-doped Weyl semimetal candidate MoTe2Dec 27 2015Dec 29 2015Two-dimensional (2D) transition-metal dichalcogenide (TMDs) MoTe2 has attracted much attention due to its predicted Weyl semimetal (WSM) state and a quantum spin Hall insulator in bulk and monolayer form, respectively. We find that the superconductivity ... More
Repetition rate tuning of soliton in microrod resonatorsSep 18 2018The coherent temporal soliton in optical microresonators has attracted great attention recently. Here, we demonstrate the dissipative Kerr soliton generation in a microrod resonator, by utilizing an auxiliary-laser-assisted thermal response control. By ... More
Bell inequality for qubits based on the Cauchy-Schwarz inequalityAug 17 2008Jan 14 2009We develop a systematic approach to establish Bell inequalities for qubits based on the Cauchy-Schwarz inequality. We also use the concept of distinct "roots" of Bell function to classify some well-known Bell inequalities for qubits. As applications of ... More