Results for "Kun Zhou"

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Blocks with defect group $\mathbb Z_{2^n}\times \mathbb Z_{2^n}\times \mathbb Z_{2^m}$Mar 20 2018Jun 26 2018In this paper, we prove that a block with defect group $\mathbb Z_{2^n}\times \mathbb Z_{2^n}\times \mathbb Z_{2^m}$, where $n\geq 2$ and $m$ is arbitrary, is Morita equivalent to its Brauer correspondent.
Boosted Sparse and Low-Rank Tensor RegressionNov 03 2018We propose a sparse and low-rank tensor regression model to relate a univariate outcome to a feature tensor, in which each unit-rank tensor from the CP decomposition of the coefficient tensor is assumed to be sparse. This structure is both parsimonious ... More
Experimental observation of exceptional surface in synthetic dimensions with magnon polaritonsMay 31 2019Exceptional points (EPs) are singularities of energy levels in non-Hermitian systems. In this Letter, we demonstrate the surface of EPs on a magnon polariton platform composed of coupled magnons and microwave photons. Our experiments show that EPs form ... More
Superior thermal conductivity and extremely high mechanical strength in polyethylene chains from {\it ab initio} calculationMar 15 2012Mar 22 2013The upper limit of the thermal conductivity and the mechanical strength are predicted for the polyethylene chain, by performing the {\it ab initio} calculation and applying the quantum mechanical non-equilibrium Green's function approach. Specially, there ... More
Spin Waves in Random Spin ChainsAug 30 2002We study quantum spin-1/2 Heisenberg ferromagnetic chains with dilute, random antiferromagnetic impurity bonds with modified spin-wave theory. By describing thermal excitations in the language of spin waves, we successfully observe a low-temperature Curie ... More
Antiferromagnetic Chern insulators in non-centrosymmetric systemsOct 13 2017Mar 21 2018We investigate a new class of topological antiferromagnetic (AF) Chern insulators driven by electronic interactions in two-dimensional systems without inversion symmetry. Despite the absence of a net magnetization, AF Chern insulators (AFCI) possess a ... More
Deep Interest Evolution Network for Click-Through Rate PredictionSep 11 2018Nov 16 2018Click-through rate~(CTR) prediction, whose goal is to estimate the probability of the user clicks, has become one of the core tasks in advertising systems. For CTR prediction model, it is necessary to capture the latent user interest behind the user behavior ... More
Ni/Ni3C Core-Shell Nanochains and Its Magnetic Properties: One-Step Synthesis at low temperatureDec 11 2008One-dimensional Ni/Ni3C core-shell nanoball chains with an average diameter by around 30 nm were synthesized by means of a mild chemical solution method using a soft template of trioctylphosphineoxide (TOPO). It was revealed that the uniform Ni nanochains ... More
FBI-Pose: Towards Bridging the Gap between 2D Images and 3D Human Poses using Forward-or-Backward InformationJun 25 2018Although significant advances have been made in the area of human poses estimation from images using deep Convolutional Neural Network (ConvNet), it remains a big challenge to perform 3D pose inference in-the-wild. This is due to the difficulty to obtain ... More
Res-embedding for Deep Learning Based Click-Through Rate Prediction ModelingJun 25 2019Recently, click-through rate (CTR) prediction models have evolved from shallow methods to deep neural networks. Most deep CTR models follow an Embedding\&MLP paradigm, that is, first mapping discrete id features, e.g. user visited items, into low dimensional ... More
Domain Adaptive Dialog Generation via Meta LearningJun 08 2019Domain adaptation is an essential task in dialog system building because there are so many new dialog tasks created for different needs every day. Collecting and annotating training data for these new tasks is costly since it involves real user interactions. ... More
Hidden thermal structure in Fock spaceAug 02 2018The emergence of quantum statistical mechanics from individual pure states of closed many-body systems is currently under intensive investigations. While most efforts have been put on the impacts of the direct interaction (i.e., the usual mutual interaction) ... More
Actively switchable non-degenerate polarization entangled photon pair distribution in a dense wave-division multiplexingJan 22 2013We have realized experimentally a non-degenerate polarization-entangled photon pair distribution in a commercial telecom dense wave-division multiplexing device (DWDM) with 8 channels. A promising point of this work is that the entangled photon pair is ... More
Frequency-oriented sub-sampling by photonic Fourier transform and I/Q demodulationJul 12 2017Sub-sampling can acquire directly a passband within a broad radio frequency (RF) range, avoiding down-conversion and low-phase-noise tunable local oscillation (LO). However, sub-sampling suffers from band folding and self-image interference. In this paper ... More
Full-duplex Amplify-and-Forward Relaying: Power and Location OptimizationMar 21 2017In this paper, we consider a full-duplex (FD) amplify-and-forward (AF) relay system and optimize its power allocation and relay location to minimize the system symbol error rate (SER). We first derive the asymptotic expressions of the outage probability ... More
Charged Higgs Pair Production at the LHC as a Probe of the Top-Seesaw Assisted Technicolor ModelsJan 08 2015May 29 2015The top-seesaw assisted technicolor (TC) model, which was proposed recently to explain the 126 GeV Higgs mass discovered by the Large Hadron Colliders (LHC), predicts light and heavy charged Higgs bosons in addition to the neutral Higgses. In this paper ... More
Exploring the Charge Localization and Band Gap Opening of Borophene: A First-Principles StudyDec 13 2017Recently synthesized two-dimensional (2D) boron, borophene, exhibits a novel metallic behavior rooted in the s-p orbital hybridization, distinctively different from other 2D materials such as sulfides/selenides and semi-metallic graphene. This unique ... More
Multi-View Graph Convolutional Network and Its Applications on Neuroimage Analysis for Parkinson's DiseaseMay 22 2018May 07 2019Parkinson's Disease (PD) is one of the most prevalent neurodegenerative diseases that affects tens of millions of Americans. PD is highly progressive and heterogeneous. Quite a few studies have been conducted in recent years on predictive or disease progression ... More
Phase-controlled dual-comb coherent anti-Stokes Raman spectroscopic imagingFeb 11 2017Coherent Raman microscopy provide label-free imaging by interrogating the intrinsic vibration of biomolecules. Nevertheless, trade-off between high chemical-specificity and high imaging-speed currently exists in transition from spectroscopy to spectroscopic ... More
Full-range Gate-controlled Terahertz Phase Modulations with Graphene MetasurfacesSep 24 2014Sep 26 2014Local phase control of electromagnetic wave, the basis of a diverse set of applications such as hologram imaging, polarization and wave-front manipulation, is of fundamental importance in photonic research. However, the bulky, passive phase modulators ... More
Environmental Stability of Bismuthene: Oxidation Mechanism and Structural Stability of 2D PnictogensJul 10 2019Recently a new group of two dimensional (2D) materials, originating from the group V elements (pnictogens), has gained global attention owing to their outstanding properties.
Metamaterial Perfect Absorber Analyzed by a Meta-cavity Model Consisting of Multilayer MetasurfacesMay 07 2017We demonstrate that the metamaterial perfect absorber behaves as a meta-cavity bounded between a resonant metasurface and a metallic thin-film reflector. The perfect absorption is achieved by the Fabry-Perot cavity resonance via multiple reflections between ... More
Exit momentum and instantaneous ionization rate of nonadiabatic tunneling ionization in elliptically polarized laser fieldsMay 15 2019Based on the strong-field approximation, we obtain analytical expressions for the initial momentum at the tunnel exit and instantaneous ionization rate of tunneling ionization in elliptically polarized laser fields with arbitrary ellipticity. The tunneling ... More
Adaptive wavefront correction of dynamic multimode beam based on modal decompositionMar 24 2019We propose and demonstrate a method for the adaptive wavefront correction of dynamic multimode fiber beams for the first time. The wavefront of incident beam is reconstructed in real-time based on the complete modal information, which obtained by using ... More
Ultra-broadband continuously-tunable polarization entangled photon pair source covering the C+L telecom bands based on a single type-II PPKTP crystalNov 19 2012Jan 18 2013In this work, we report on the preparation of an ultra-broadband continuously-tunable, highly polarization-entangled photon-pair source covering the C+L telecom bands using a single type-II phase-matched bulk PPKTP crystal. Over 60 nm turning band of ... More
Efficient spectrum prediction and inverse design for plasmonic waveguide systems based on artificial neural networksMay 16 2018Nov 11 2018In this article, we propose a novel approach to achieve spectrum prediction, parameter fitting, inverse design and performance optimization for the plasmonic waveguide coupled with cavities structure (PWCCS) based on artificial neural networks (ANNs). ... More
Raman pulse duration effect in gravity gradiometers composed of two atom interferometersMar 04 2015We investigated the Raman pulse duration effect in a gravity gradiometer with two atom interferometers. Since the two atom clouds in the gradiometer experience different gravitational fields, it is hard to compensate the Doppler shifts of the two clouds ... More
Observation of optical filtering effects with four-wave mixing in a cold atomic ensembleOct 29 2014Oct 30 2014We observe an optical filtering effect in four-wave mixing (FWM) process based on a cold atomic gas. The side peaks appear at the edges of pulse of generated optical field, and they propagate through the atomic media without absorption. The theoretical ... More
Fringe-locking method for the weak equivalence principle test by simultaneous dual-species atom interferometersMar 04 2016We theoretically investigate the application of the fringe-locking method (FLM) in the dual-species quantum test of the weak equivalence principle (WEP). With the FLM, the measurement is performed invariably at the midfringe, and the extraction of the ... More
Honest Confidence Sets for High-Dimensional Regression by Projection and ShrinkageFeb 01 2019The issue of honesty in constructing confidence sets arose in nonparametric regression. While optimal rate in nonparametric estimation can be achieved and utilized to construct sharp confidence sets, severe degradation of confidence level often happens ... More
Large-Scale Speaker Diarization of Radio Broadcast ArchivesJun 19 2019Jun 28 2019This paper describes our initial efforts to build a large-scale speaker diarization (SD) and identification system on a recently digitized radio broadcast archive from the Netherlands which has more than 6500 audio tapes with 3000 hours of Frisian-Dutch ... More
Crafting GBD-Net for Object DetectionOct 08 2016The visual cues from multiple support regions of different sizes and resolutions are complementary in classifying a candidate box in object detection. Effective integration of local and contextual visual cues from these regions has become a fundamental ... More
Honest confidence sets for high-dimensional regression by projection and shrinkageFeb 01 2019May 03 2019The issue of honesty in constructing confidence sets arises in nonparametric regression. While optimal rate in nonparametric estimation can be achieved and utilized to construct sharp confidence sets, severe degradation of confidence level often happens ... More
Star Forming Regions in CassiopeiaSep 27 2008This chapter describes the Galactic star forming regions in the constellation Cassiopeia, in the Galactic coordinate range 120 deg < l < 130 deg, -5 deg < b < +15 deg. At b > 10 deg the nearby clouds L1333 and L1340 are found in this region. The local ... More
On Invariants of $\text{C}^*$-algebras with the ideal propertyOct 04 2015Oct 12 2016In this paper, we consider $\text{C}^*$-algebras with the ideal property (the ideal property unifies the simple and real rank zero cases). We define two categories related the invariants of the $\text{C}^*$-algebras with the ideal property. And we showed ... More
Topological Rigidity for FJ by the Infinite Cyclic GroupDec 03 2015Feb 17 2016We call a group FJ if it satisfies the $K$- and $L$-theoretic Farrell-Jones conjecture with coefficients in $\mathbb Z$. We show that if $G$ is FJ, then the simple Borel conjecture (in dimensions $\ge 5$) holds for every group of the form $G\rtimes\mathbb ... More
Phase Diagrams of Spinor Bose GasesJul 27 2009Using effective field theories dictated by the symmetry of the system, as well as microscopic considerations, we map out the magnetic coupling-temperature phase diagrams of spin-1 Bose gases in both two- and three-dimensions. We also determine the nature ... More
Field Theoretical Description of Quantum Hall Edge ReconstructionFeb 17 2003We propose a generalization of the chiral Luttinger liquid theory to allow for a unified description of quantum Hall edges with or without edge reconstruction. Within this description edge reconstruction is found to be a quantum phase transition in the ... More
Inhomogeneous superconducting state in quasi-one-dimensional systemsDec 20 2000We report on results of theoretical study of non-uniform superconducting states in quasi-one-dimensional systems, with attractive interactions and Zeeman splitting between electron spins. Using bosonization to treat intrachain electron-electron interactions, ... More
Spectroscopic studies of star forming regionsDec 14 2006This paper reviews the results of studies of star forming regions, carried out at the Konkoly Observatory in the last two decades. The studies involved distance determination of star-forming dark clouds, search for candidate pre-main sequence stars, and ... More
Realization, Characterization, and Detection of Novel Superfluid Phases with Pairing between Unbalanced Fermion SpeciesMar 08 2006Mar 28 2007In this chapter we review recent experimental and theoretical work on various novel superfluid phases in fermion systems, that result from pairing fermions of different species with unequal densities. After briefly reviewing existing experimental work ... More
Thermopower as a Probe of Non-Abelian Quasiparticle Statistics in Fractional Quantum Hall StatesJul 21 2008Jan 11 2009This paper has been superseded by a new preprint: Kun Yang and Bertrand I. Halperin, arXiv:0901.1429.
Spontaneous Symmetry Breaking and Quantum Hall Effect in GrapheneMar 28 2007Jun 08 2007In this article we briefly review recent experimental and theoretical work on quantum Hall effect in graphene, and argue that some of the quantum Hall states exhibit spontaneous symmetry breaking that is driven by electron-electron interaction. We will ... More
Realization and Detection of Fulde-Ferrell-Larkin-Ovchinnikov Superfluid Phases in Trapped Atomic Fermion SystemsApr 26 2005Nov 18 2005In a very interesting recent Letter\cite{machida}, the authors suggested the possibility of realizing the spatially modulated, or Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superfluid state in trapped atomic fermion systems. The authors this Letter used ... More
Simple one-pass algorithm for penalized linear regression with cross-validation on MapReduceJun 28 2013Apr 14 2016In this paper, we propose a one-pass algorithm on MapReduce for penalized linear regression \[f_\lambda(\alpha, \beta) = \|Y - \alpha\mathbf{1} - X\beta\|_2^2 + p_{\lambda}(\beta)\] where $\alpha$ is the intercept which can be omitted depending on application; ... More
On passage to over-groups of finite indices of the Farrell-Jones conjectureDec 05 2015We use the controlled algebra approach to study the problem that whether the Farrell-Jones conjecture is closed under passage to over-groups of finite indices. Our study shows that this problem is closely related to a general problem in algebraic $K$- ... More
Early spectroscopy and photometry of the new outburst of V1647 OriSep 27 2008Broad-band photometric and moderate-resolution spectroscopic observations of the young eruptive star V1647 Ori, obtained between 28 August and 1 September 2008, are presented. The observed magnitudes and emission line equivalent widths of the star indicate ... More
On sofic approximations of Property (T) groupsJun 13 2016We prove Bowen's conjecture that every sequence of finite graphs that locally converges to the Cayley graph of a countably infinite group with Kazhdan Property (T) is essentially a vertex-disjoint union of expander graphs. We characterize graph sequences ... More
Holographic complexity of Born-Infeld black holesOct 04 2018Nov 27 2018In this paper, according to CA duality, we calculate the late time complexity growth of Born-Infeld (BI) black holes, including BI black holes in massive gravity, magnetic BI black holes and dyonic BI black hole in four dimensions. We study the effects ... More
Hairy black holes of Lovelock-Born-Infeld-Scalar gravityApr 29 2018Jul 27 2018In this paper we construct new hairy black holes of Lovelock-Born-Infeld-Scalar gravity in diverse dimensions. We study horizon structures of the black holes and find the black holes may possess three horizons, two horizons or one horizon. We give the ... More
Ferromagnetic Transition in One-Dimensional Itinerant Electron SystemsJan 09 2004Aug 04 2004We use bosonization to derive the effective field theory that properly describes ferromagnetic transition in one-dimensional itinerant electron systems. The resultant theory is shown to have dynamical exponent z=2 at tree leve and upper critical dimension ... More
Spin mapping, phase diagram, and collective modes in double layer quantum Hall systems at $ν=2$Mar 30 1999An exact spin mapping is identified to simplify the recently proposed hard-core boson description (Demler and Das Sarma, Phys. Rev. Lett., to be published) of the bilayer quantum Hall system at filling factor 2. The effective spin model describes an easy-plane ... More
Connecting phase transition theory with unsupervised learningDec 15 2017Entropy and order parameter are two key concepts in phase transition theory. This paper proposes an unified method to both find order parameter and estimate entropy automatically with unsupervised learning. The contributions of this paper are threefold: ... More
Detection of Striped Superconductors Using Magnetic Field Modulated Josephson EffectMar 29 2009Jul 15 2013In a very interesting recent Letter\cite{berg}, the authors suggested that a novel form of superconducting state is realized in La$_{2-x}$Ba$_x$CuO$_4$ with $x$ close to 1/8. This suggestion was based on experiments\cite{li} on this compound which found ... More
Dipolar Excitons, Spontaneous Phase Coherence, and Superfluid-Insulator Transition in Bi-layer Quantum Hall Systems at $ν=1$Apr 04 2001The spontaneous interlayer phase coherent (111) state of bi-layer Quantum Hall system at filling factor $\nu=1$ may be viewed as a condensate of interlayer particle-hole pairs or excitons. We show in this paper that when the layers are biased in such ... More
Acoustic Wave Absorption as a Probe of Dynamical Geometrical Response of Fractional Quantum Hall LiquidsAug 06 2015Apr 16 2016We show that acoustic crystalline wave gives rise to an effect similar to that of a gravitational wave to an electron gas. Applying this idea to a two-dimensional electron gas in the fractional quantum Hall regime, this allows for experimental study of ... More
Geometry of Compressible and Incompressible Quantum Hall States: Application to Anisotropic Composite Fermion LiquidsSep 11 2013Dec 11 2013Haldane's geometrical description of fractional quantum Hall states is generalized to compressible states. It is shown that anisotropy in the composite fermion Fermi surface is a direct reflection of this intrinsic geometry. A simple model is introduced ... More
Least Absolute Gradient Selector: Statistical Regression via Pseudo-Hard ThresholdingApr 11 2012Oct 19 2012Variable selection in linear models plays a pivotal role in modern statistics. Hard-thresholding methods such as $l_0$ regularization are theoretically ideal but computationally infeasible. In this paper, we propose a new approach, called the LAGS, short ... More
Constraints, MMSNP and expander relational structuresJun 12 2007Mar 13 2013We give a poly-time construction for a combinatorial classic known as Sparse Incomparability Lemma, studied by Erdos, Lovasz, Nesetril, Rodl and others: We show that every Constraint Satisfaction Problem is poly-time equivalent to its restriction to structures ... More
Neutron-capture elements in the s- and r-process-rich stars: Constraints on neutron-capture nucleosynthesis processesMay 14 2006The chemical abundances of the very metal-poor double-enhanced stars are excellent information for setting new constraints on models of neutron-capture processes at low metallicity. These stars are known as s+r stars, since they show enhancements of both ... More
Probing valley filtering effect by Andreev reflection in zigzag graphene nanoribbonJul 03 2017Jul 05 2017Ballistic point contact (BPC) with zigzag edges in graphene is a main candidate of a valley filter, in which the polarization of the valley degree of freedom can be selected by using a local gate voltage. Here, we propose to detect the valley filtering ... More
A comprehensive study of the magnetic, structural and transport properties of the III-V ferromagnetic semiconductor InMnPJan 15 2015The manganese induced magnetic, electrical and structural modification in InMnP epilayers, prepared by Mn ion implantation and pulsed laser annealing, are investigated in the following work. All samples exhibit clear hysteresis loops and strong spin polarization ... More
Terabit optical OFDM superchannel transmission via coherent carriers of a hybrid chip-scale soliton frequency combApr 28 2018We demonstrate seamless channel multiplexing and high bitrate superchannel transmission of coherent optical orthogonal-frequency-division-multiplexing (CO-OFDM) data signals utilizing a dissipative Kerr soliton (DKS) frequency comb generated in an on-chip ... More
Lifelong Sequential Modeling with Personalized Memorization for User Response PredictionMay 02 2019May 12 2019User response prediction, which models the user preference w.r.t. the presented items, plays a key role in online services. With two-decade rapid development, nowadays the cumulated user behavior sequences on mature Internet service platforms have become ... More
Quantum Storage of Orbital Angular Momentum Entanglement in an Atomic EnsembleApr 02 2014Constructing a quantum memory for a photonic entanglement is vital for realizing quantum communication and network. Besides enabling the realization of high channel capacity communication, entangled photons of high-dimensional space are of great interest ... More
Grid-converged Solution and Analysis of the Unsteady Viscous Flow in a Two-dimensional Shock TubeMay 25 2017The flow in a shock tube is extremely complex with dynamic multi-scale structures of sharp fronts, flow separation, and vortices due to the interaction of the shock wave, the contact surface, and the boundary layer over the side wall of the tube. Prediction ... More
Testing the Universality of Free Fall at ${10^{ - 10}}$ level by Comparing the Atoms in Different Hyperfine States with Bragg DiffractionMay 20 2018May 31 2018We have performed a precision atomic interferometry experiment on testing the universality of free fall (UFF) considering atoms' spin degree of freedom. Our experiment employs the Bragg atom interferometer with $^{87}$Rb atoms either in hyperfine state ... More
Textured electronic states of the triangular lattice Hubbard model and Na$_x$CoO$_2$Sep 02 2013Nov 03 2014We show that geometric frustration and strong correlation in the triangular lattice Hubbard model lead a rich and novel phase structure of $\sqrt{3}\times\sqrt{3}$ spin-charge textured electronic states over a wide region of electron doping $0\le x \le ... More
Mass transfer in Frenkel-Kontorova chain initiated by molecule impactMay 18 2018The Frenkel-Kontorova chain with a free end is used to study initiation and propagation of crowdions (anti-kinks) caused by impact of a molecule consisting of K atoms. It is found that molecules with 1 < K < 10 are more efficient in initiation of crowdions ... More
Generation of light with controllable spatial patterns via the sum frequency in quasi-phase matching crystalsMay 08 2014Light beams with extraordinary spatial structures, such as the Airy beam (AB), the Bessel-Gaussian beam (BGB) and the Laguerre-Gaussian beam (LGB), are widely studied and applied in many optical scenarios. We report on preparation of light beams with ... More
Disorder and Power-law Tails of DNA Sequence Self-Alignment Concentrations in Molecular EvolutionNov 20 2014Dec 20 2014The self-alignment concentrations, $c(x)$, as functions of the length, $x$, of the identically matching maximal segments in the genomes of a variety of species, typically present power-law tails extending to the largest scales, i.e., $c(x) \propto x^{\alpha}$, ... More
Activated dissociation of O2 on Pb(111) surfaces by Pb adatomsAug 22 2009Oct 27 2011We investigate the dissociation of O2 on Pb(111) surface using first-principles calculations. It is found that in a practical high-vacuum environment, the adsorption of molecular O2 takes place on clean Pb surfaces only at low temperatures such as 100 ... More
Cell Size Effect on Computational Fluid Dynamics: The Limitation Principle for Flow SimulationJun 26 2017May 25 2018For theoretical gas dynamics, the flow regimes are classified according to the Knudsen number. For computational fluid dynamics (CFD), the numerical flow field is the projection of the physical flow field onto the discrete space and time, which is related ... More
Simplification of the Flux Function for a Higher-order Gas-kinetic Evolution ModelOct 04 2016The higher-order gas-kinetic scheme for solving the Navier-Stokes equations has been studied in recent years. In addition to the use of higher-order reconstruction techniques, many terms are used in the Taylor expansion of the gas distribution functions. ... More
Test of the universality of free fall with atoms in different spin OrientationsMar 02 2015We report a test of the universality of free fall (UFF) related to spin-gravity coupling effects by comparing the gravity acceleration of the $^{87}$Rb atoms in $m_F=+1$ versus that in $m_F=-1$, where the corresponding spin orientations are opposite. ... More
An optical fan for light beams for high-precision optical measurements and optical switchingMay 08 2014The polarization and orbital angular momentum properties of light are of great importance in optical science and technology in the fields of high precision optical measurements and high capacity and high speed optical communications. Here we show, a totally ... More
Object Tracking in Hyperspectral Videos with Convolutional Features and Kernelized Correlation FilterOct 28 2018Target tracking in hyperspectral videos is a new research topic. In this paper, a novel method based on convolutional network and Kernelized Correlation Filter (KCF) framework is presented for tracking objects of interest in hyperspectral videos. We extract ... More
Analysis on the computability over the efficient utilization problem of the four-dimensional space-timeJul 21 2011This paper formally proposes a problem about the efficient utilization of the four dimensional space-time. Given a cuboid container, a finite number of rigid cuboid items, and the time length that each item should be continuous baked in the container, ... More
Feynman's solution of the quintessential problem in solid state physicsSep 12 2018May 13 2019Two of the most influential ideas developed by Richard Feynman are the Feynman diagram technique and his variational approach. The former provides a powerful tool to construct a systematic expansion for a generic interacting system, while the latter allows ... More
Timely-Throughput Optimal Scheduling with PredictionDec 15 2017Jan 05 2018Motivated by the increasing importance of providing delay-guaranteed services in general computing and communication systems, and the recent wide adoption of learning and prediction in network control, in this work, we consider a general stochastic single-server ... More
Large Spin Formation and Thermodynamic Properties of Disordered Spin Ladders with Site DilutionAug 23 2002Apr 10 2003Low temperature properties of antiferromagnetic two-leg spin-1/2 ladders with bond randomness and site dilution (or doping with nonmagnetic impurities) are studied using the real-space renormalization-group technique. We find that for non zero doping ... More
A Survey on Neural Network Language ModelsJun 09 2019Jun 13 2019As the core component of Natural Language Processing (NLP) system, Language Model (LM) can provide word representation and probability indication of word sequences. Neural Network Language Models (NNLMs) overcome the curse of dimensionality and improve ... More
Coulomb interaction driven instabilities of sliding Luttinger liquidsMay 01 2017Aug 21 2017We study systems made of periodic arrays of one dimensional quantum wires, coupled by Coulomb interaction. Using bosonization an interacting metallic fixed point is obtained, which is shown to be a higher dimensional analogue of the Tomonaga-Luttinger ... More
Quantized Magnetic Flux and the Magneto-halon Effect in a Critical SuperconductorAug 21 2018Employing the standard worldline-vortex mapping, we conclude that at the critical temperature, superconductors demonstrate the magneto-halon effect with respect to the quantized net magnetic flux generated by a solenoid inserted into the system. The effect ... More
Robust Reduced Rank RegressionSep 14 2015Jul 15 2017In high-dimensional multivariate regression problems, enforcing low rank in the coefficient matrix offers effective dimension reduction, which greatly facilitates parameter estimation and model interpretation. However, commonly-used reduced-rank methods ... More
NP by means of lifts and shadowsJun 23 2007We show that every NP problem is polynomially equivalent to a simple combinatorial problem: the membership problem for a special class of digraphs. These classes are defined by means of shadows (projections) and by finitely many forbidden colored (lifted) ... More
Convergence Analysis of the Frank-Wolfe Algorithm and Its Generalization in Banach SpacesOct 19 2017The Frank-Wolfe algorithm, a very first optimization method and also known as the conditional gradient method, was introduced by Frank and Wolfe in 1956. Due to its simple linear subproblems, the Frank-Wolfe algorithm has recently been received much attention ... More
Halperin (m, m',n) bilayer quantum Hall states on thin cylindersJan 15 2008Sep 06 2008The Halperin $(m,m',n)$ bilayer quantum Hall states are studied on thin cylinders. In this limit, charge density wave patterns emerge that are characteristic of the underlying quantum Hall state. The general patterns are worked out from a variant of the ... More
Bond-randomness-induced Neel order in weakly coupled antiferromagnetic spin chainsJul 25 2002May 21 2003Quasi-one-dimensional antiferromagnetic (AF) quantum spin systems show a wide range of interesting phenomena such as the spin-Peierls transition and disorder driven long range ordering. While there is no magnetic long range order in strictly one-dimensional ... More
Entanglement spectrum and entangled modes of highly excited states in random XX spin chainsAug 24 2015Jan 12 2016We examine the real space renormalization group method of finding \textit{excited eigenstate} (RSRG-X) of the XX spin-1/2 chain, from entanglement perspectives. Eigenmodes of entanglement Hamiltonian, especially the maximally entangled mode and corresponding ... More
Entanglement spectrum and entangled modes of random XX spin chainsApr 22 2013Aug 25 2013We study in this work the ground state entanglement properties of finite XX spin-1/2 chains with random couplings, using Jordan-Wigner transformation. We divide the system into two parts and study reduced density matrices (RDMs) of its subsystems. Due ... More
Fractionalization via $\mathbb{Z}_{2}$ Gauge Fields at a Cold Atom Quantum Hall TransitionNov 30 2010We study a single species of fermionic atoms in an "effective" magnetic field at total filling factor $\nu_{f}=1$, interacting through a p-wave Feshbach resonance, and show that the system undergoes a quantum phase transition from a $\nu_{f} =1 $ fermionic ... More
Thermopower of Quantum Hall States in Corbino Geometry as a Measure of Quasiparticle EntropyFeb 18 2012Using the Onsager relation between electric and heat transport coefficients, and considering the very different roles played by the quantum Hall condensate and quasiparticles in transport, we argue that near the center of a quantum Hall plateau thermopower ... More
Age-of-Information in the Presence of ErrorMay 02 2016We consider the peak age-of-information (PAoI) in an M/M/1 queueing system with packet delivery error, i.e., update packets can get lost during transmissions to their destination. We focus on two types of policies, one is to adopt Last-Come-First-Served ... More
Even-Odd effect of an Spin-S impurity coupled to a quantum critical systemOct 30 2018We discuss an even-odd effect for an impurity with an $N$-fold degenerate internal states immersed in a two-dimensional superfluid--Mott-insulator quantum critical bath, which is described by an spin-$S$ XY Bose-Kondo impurity model with $N=2S+1$. Using ... More
Dynamics of weakly coupled random antiferromagnetic quantum spin chainsFeb 22 2005Jul 18 2005We study the low-energy collective excitations and dynamical response functions of weakly coupled random antiferromagnetic spin-1/2 chains. The interchain coupling leads to Neel order at low temperatures. We use the real-space renormalization group technique ... More
Random Antiferromagnetic Spin-1/2 Chains with Competing InteractionsMar 11 2003Aug 05 2003We study disordered antiferromagnetic spin-1/2 chains with nearest- and further-neighbor interactions using the real-space renormalization-group method. We find that the system supports two different phases, depending on the ratio of the strength between ... More
An extension of Hsiung-Minkowski formulas and its applicationsJul 11 2013Jul 16 2014We prove a generalization of Hsiung-Minkowski formulas for closed submanifolds in semi-Riemannian manifolds with constant curvature. As a corollary, we obtain volume and area upper bounds for k-convex hypersurfaces in terms of a weighted total k-th mean ... More
Quadratic Twists of Elliptic Curves with 3-Selmer Rank 1Nov 21 2013A weaker form of a 1979 conjecture of Goldfeld states that for every elliptic curve $E/\mathbb{Q}$, a positive proportion of its quadratic twists $E^{(d)}$ have rank 1. Using tools from Galois cohomology, we give criteria on E and d which force a positive ... More
Microscopy for Atomic and Magnetic Structures Based on Thermal Neutron Fourier-transform Ghost ImagingJan 29 2018Mar 02 2018We present a lensless, Fourier-transform ghost imaging scheme by exploring the fourth-order correlation function of spatially incoherent thermal neutron waves. This technique is established on the Fermi-Dirac statistics and the anti-bunching effect of ... More