Results for "Q. Niu"

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Nuclear effective charge factor originating from covariant density functional theoryMay 24 2013Guiding by the relativistic local density approximation, we explore a phenomenological formula for the coupling strength of Coulomb field to take into account the Coulomb exchange term effectively in the relativistic Hartree approximation. Its validity ... More
Nuclear $β^+$/EC decays in covariant density functional theory and the impact of isoscalar proton-neutron pairingMay 23 2013Self-consistent proton-neutron quasiparticle random phase approximation based on the spherical nonlinear point-coupling relativistic Hartree-Bogoliubov theory is established and used to investigate the $\beta^+$/EC-decay half-lives of neutron-deficient ... More
Quantized Density Response in InsulatorsMar 18 1994The response of particle density to a dilation of a periodic potential in an insulator, with or without a fixed background potential or a magnetic field, is shown to be quantized. A similar phenomenon occurs in a quantum Hall system, where the derivative ... More
Emergence and stability of spontaneous vortex lattices in exciton-polariton condensatesJan 10 2019Jan 11 2019The spontaneous formation of lattice structure of quantized vortices is a characteristic feature of superfluidity in closed systems under thermal equilibrium. In exciton-polariton Bose-Einstein condensate, which is a typical example of macroscopic quantum ... More
Strong photon blockade with intracavity electromagnetically induced transparency in blockaded Rydberg ensembleAug 13 2013Dec 14 2015We consider the dynamics of intracavity electromagnetically induced transparency (EIT) in an ensemble of strongly interacting Rydberg atoms. By combining the advantage of variable cavity lifetimes with intracavity EIT and strongly interacting Rydberg ... More
Rate-Compatible Punctured Polar Codes: Optimal Construction Based on Polar SpectraDec 05 2016Dec 03 2017Polar codes are the first class of constructive channel codes achieving the symmetric capacity of the binary-input discrete memoryless channels. But the corresponding code length is limited to the power of two. In this paper, we establish a systematic ... More
Tunable ultranarrow linewidth of cavity induced by interacting dark resonancesJun 17 2009A scheme for getting a tunable ultranarrow linewidth of a cavity due to an embedded four-level atomic medium with double-dark resonances is proposed. It is shown that the steep dispersion induced by double-dark resonances in the transparency window leads ... More
Cavity linewidth narrowing with dark-state polaritonsAug 14 2013Apr 09 2015We perform a quantum-theoretical treatment of cavity linewidth narrowing with intracavity electromagnetically induced transparency (EIT). By means of intracavity EIT, the photons in the cavity are in the form of cavity polaritons: bright-state polariton ... More
Systematic calculations of $α$-decay half-lives with an improved empirical formulaMar 05 2015Based on the recent data in NUBASE2012, an improved empirical formula for evaluating the $\alpha$-decay half-lives is presented, in which the hindrance effect resulted from the change of the ground state spins and parities of parent and daughter nuclei ... More
Global dynamical correlation energies in covariant density functional theory: cranking approximationMay 08 2013Jan 20 2014The global dynamical correlation energies for 575 even-even nuclei with proton numbers ranging from Z=8 to Z=108 calculated with the covariant density functional theory using the PC-PK1 parametrization are presented. The dynamical correlation energies ... More
Aharonov-Bohm and Aharonov-Casher Effects: Connections to Dynamics of Topological SingularitiesMar 10 1998We analyze the physical processes involved in the Aharonov-Bohm (A-B) and the Aharonov-Casher (A-C) effects, showing that an incomplete A-B effect knowledge can lead a totally wrong conclusion on the A-C effect. Based on this we demonstrate that the Magnus ... More
Tellurene-a monolayer of tellurium from first-principles predictionMay 11 2016A two dimensional (2D) Group-VI Te monolayer, tellurene, is predicted by using the first-principles calculations, which consists of planner four-membered and chair-like six-membered rings arranged alternately in a 2D lattice. The phonon spectra calculations, ... More
Berry phase, hyperorbits, and the Hofstadter spectrumMay 04 1995We develop a semiclassical theory for the dynamics of electrons in a magnetic Bloch band, where the Berry phase plays an important role. This theory, together with the Boltzmann equation, provides a framework for studying transport problems in high magnetic ... More
Local Density of States and Level Width for Wannier-Stark LaddersJul 21 1993The local density of states \rho(x,E) is calculated for a Bloch electron in an electric field. Depending on the system size, we can see one or more sequences of Wannier-Stark ladders in \rho(x,E), with Lorentz type level widths and apparent spatial localization ... More
Electron Band Structure in a Two Dimensional Periodic Magnetic FieldJul 19 1994In this paper we study the energy spectrum of a two dimensional electron gas (2DEG) in a two dimensional periodic magnetic field. Both a square magnetic lattice and a triangular one are considered. We consider the general case where the magnetic field ... More
Tunable narrow band source via the strong coupling between optical emitter and nanowire surface plasmonsDec 30 2014The spectrum width can be narrowed to a certain degree by decreasing the coupling strength for the two-level emitter coupled to the propagating surface plasmon. But the width can not be narrowed any further because of the loss of the photon out of system ... More
Berry phase, hyperorbits, and the Hofstadter spectrum: semiclassical dynamics in magnetic Bloch bandsNov 02 1995We have derived a new set of semiclassical equations for electrons in magnetic Bloch bands. The velocity and energy of magnetic Bloch electrons are found to be modified by the Berry phase and magnetization. This semiclassical approach is used to study ... More
Quantum Nondemolition Measurement and Heralded Preparation of Fock States with Electromagnetically Induced Transparency in an Optical CavityMar 01 2012Mar 29 2012We propose a technique for quantum nondemolition (QND) measurement and heralded preparation of Fock states by dynamics of electromagnetically induced transparency (EIT). An atomic ensemble trapped in an optical cavity is driven by two external continuous-wave ... More
Charge Transfer Effects in Naturally Occurring van der Waals Heterostructures (PbSe)1.16(TiSe2)m (m=1, 2)Mar 10 2018Van der Waals heterostructures (VDWHs) exhibit rich properties and thus has potential for applications, and charge transfer between different layers in a heterostructure often dominates its properties and device performance. It is thus critical to reveal ... More
Ultrabroadband photosensitivity from visible to terahertz at room temperatureJun 23 2018Charge-density wave (CDW) is one of the most fundamental quantum phenomena in solids. Different from ordinary metals in which only single particle excitations exist, CDW also has collective excitations and can carry electric current in a collective fashion. ... More
The unique electronic structure of Ca10(Pt4As8)(Fe2-xPtxAs2)5 with metallic Pt4As8 layersAug 13 2013We studied the low-lying electronic structure of the newly discovered iron-platinum-arsenide superconductor, Ca10(Pt4As8)(Fe2-xPtxAs2)5 (Tc=22 K) with angle-resolved photoemission spectroscopy. We found that the Pt4As8 layer contributes to a small electron-like ... More
The weak electronic correlations and absence of heavy Fermion state in KNi$_2$Se$_2$Nov 24 2014We have studied the low-lying electronic structure of a new ThCr$_2$Si$_2$-type superconductor KNi$_2$Se$_2$ with angle-resolved photoemission spectroscopy. Three bands intersect the Fermi level, forming complicated Fermi surface topology, which is sharply ... More
Mean dimension and AH-algebras with diagonal mapsOct 04 2010Feb 01 2014Mean dimension for AH-algebras is introduced. It is shown that if a simple unital AH-algebra with diagonal maps has mean dimension zero, then it has strict comparison on positive elements. In particular, the strict order on projections is determined by ... More
Anomalous Nernst and Hall effects in magnetized platinum and palladiumJun 04 2014We study the anomalous Nernst effect (ANE) and anomalous Hall effect (AHE) in proximity-induced ferromagnetic palladium and platinum which is widely used in spintronics, within the Berry phase formalism based on the relativistic band structure calculations. ... More
From Feynman's Wave Function to the Effective Theory of Vortex DynamicsJan 21 1994We calculate the overlap between two many-body wave functions for a superfluid film containing a vortex at shifted positions. Comparing the results to phenomenological theories, which treat vortices as point particles, we find that the results are consistent ... More
Screening, nonadiabaticity, and quantized acoustoelectric currentSep 13 1999Nov 05 1999Quantized single-electron transport driven by surface acoustic waves (SAW) through a pinched-off narrow constriction is studied theoretically. Long-range Coulomb interaction causes the tunneling coupling between the two-dimensional electron gas (2DEG) ... More
Vortex Dynamics in Superfluid Systems: Cyclotron Type MotionApr 02 1996Vortex dynamics in superfluids is investigated in the framework of the nonlinear Schr\"{o}dinger equation. The natural motion of the vortex is of cyclotron type, whose frequency is found to be on the order of phonon velocity divided by the coherence length, ... More
Dynamic Fractional Stark Ladders in DC--AC FieldsDec 09 1993Dec 09 1994A single band in a spatially periodic system splits into a series of quasienergy subbands under the action of DC--AC electric fields. These dynamic fractional Stark ladders should be observable in an investigation of optical absorption.
Highly anisotropic and two-fold symmetric superconducting gap in nematically ordered FeSe$_{0.93}$S$_{0.07}$Mar 16 2016FeSe exhibits a novel ground state in which superconductivity coexists with a nematic order in the absence of any long-range magnetic order. Here we report an angle-resolved photoemission study on the superconducting gap structure in the nematic state ... More
Pumping in an interacting quantum wireJun 06 2003We study charge and spin pumping in an interacting one-dimensional wire. We show that a spatially periodic potential modulated in space and time acts as a quantum pump inducing a dc-current component at zero bias. The current generated by the pump is ... More
Derivation of the transverse force on a moving vortex in a superfluidAug 20 1996We describe an exact derivation of the total nondissipative transverse force acting on a quantized vortex moving in a uniform background. The derivation is valid for neutral boson or fermion superfluids, provided the order parameter is a complex scalar ... More
Superconductivity across Lifshitz transition and anomalous insulating state in surface K-dosed (Li0.8Fe0.2OH)FeSeAug 18 2017In the iron-based superconductors, understanding the relation between superconductivity and electronic structure upon doping is crucial for exploring the pairing mechanism. Recently it was found that in iron selenide (FeSe), enhanced superconductivity ... More
Presence of Exotic Electronic Surface States in LaBi and LaSbJul 14 2016Nov 01 2016Extremely high magnetoresistance (XMR) in the lanthanum monopnictides La$X$ ($X$ = Sb, Bi) has recently attracted interest in these compounds as candidate topological materials. However, their perfect electron-hole compensation provides an alternative ... More
Interactions of Collective Excitations with Vortices in Superfluid SystemsDec 26 1994We investigate the interactions of collective excitations with vortices in superfluid systems, including $~^4$He and superconductors. The dynamical equations are obtained by the aid of the many-body wavefunction and the density-density correlation function. ... More
Transverse force on a quantized vortex in a superfluidMar 30 1996We have derived an exact expression for the total nondissipative transverse force acting on a quantized vortex moving in a uniform background. The derivation is valid for neutral boson or fermion superfluids, provided the order parameter is a complex ... More
From Feynman's Wave Function to the Effective Theory of Vortex DynamicsJan 21 1994We calculate the overlap between two many-body wave functions for a superfluid film containing a vortex at shifted positions. Comparing the results to phenomenological theories, which treat vortices as point particles, we find that the results are consistent ... More
Controllable spin-orbit coupling and its influence on the upper critical field in the chemically doped quasi-one-dimensional Nb$_2$PdS$_5$ superconductorSep 30 2014By systematic chemical substitution of Pt and Ni in the newly-discovered superconductor Nb$_2$PdS$_5$ ($T_c\sim$6 K), we study the evolution of its superconducting properties with doping, focussing on the behavior of the upper critical field $H_{c2}$. ... More
Observation of Fermi Arcs in non-Centrosymmetric Weyl Semi-metal Candidate NbPSep 13 2015We report the surface electronic structure of niobium phosphide NbP single crystal on (001) surface by vacuum ultraviolet angle-resolved photoemission spectroscopy. Combining with our first principle calculations, we identify the existence of the Fermi ... More
Second-order correlation function from asymmetric to symmetric transitions due to spectrally indistinguishable biexciton cascade emissionSep 23 2015We report the observed photon bunching statistics of biexciton cascade emission at zero time delay in single quantum dots by second-order correlation function measurements under continuous wave excitation. It is found that the bunching phenomenon is independent ... More
Electronic structure of FeSMar 25 2017Here we report the electronic structure of FeS, a recently identified iron-based superconductor. Our high-resolution angle-resolved photoemission spectroscopy studies show two hole-like ($\alpha$ and $\beta$) and two electron-like ($\eta$ and $\delta$) ... More
Evidence for two energy gaps and Fermi liquid behavior in SrPt$_2$As$_2$ superconductorApr 08 2013We report a detailed calorimetric study on single crystals of the 5$d$-transition metal pnictide SrPt2As2 with a superconducting critical temperature $T_c$ $\sim$5K. The peculiar field dependence of the electronic specific heat coefficient $\gamma$ can ... More
Electronic structure and 4f-electron character in Ce2PdIn8 studied by angle-resolved photoemission spectroscopyFeb 15 2019The localized-to-itinerant transition of f electrons lies at the heart of heavy-fermion physics, but has only been directly observed in single-layer Ce-based materials. Here, we report a comprehensive study on the electronic structure and nature of the ... More
Surface electronic structure and evidence of plain s-wave superconductivity in (Li0.8Fe0.2)OHFeSeJul 09 2015Oct 04 2016(Li0.8Fe0.2)OHFeSe is a newly-discovered intercalated iron-selenide superconductor with a Tc above 40 K, which is much higher than the Tc of bulk FeSe (8 K). Here we report a systematic study of (Li0.8Fe0.2)OHFeSe by low temperature scanning tunneling ... More
Unveiling the superconducting mechanism of Ba$_{0.51}$K$_{0.49}$BiO$_3$Feb 28 2018Bismuthates were the first family of oxide high-temperature superconductors, exhibiting superconducting transition temperatures (Tc) up to 32K, but the superconducting mechanism remains under debate despite more than 30 years of extensive research. Our ... More
A Refined Harmonic Lanczos Bidiagonalization Method and an Implicitly Restarted Algorithm for Computing the Smallest Singular Triplets of Large MatricesJun 12 2009The harmonic Lanczos bidiagonalization method can be used to compute the smallest singular triplets of a large matrix $A$. We prove that for good enough projection subspaces harmonic Ritz values converge if the columns of $A$ are strongly linearly independent. ... More
The Nekrasov-Okounkov hook length formula: refinement, elementary proof, extension and applicationsMay 09 2008The paper is devoted to the derivation of the expansion formula for the powers of the Euler Product in terms of partition hook lengths, discovered by Nekrasov and Okounkov in their study of the Seiberg-Witten Theory. We provide a refinement based on a ... More
New hook length formulas for binary treesApr 23 2008We find two new hook length formulas for binary trees. The particularity of our formulas is that the hook length $h_v$ appears as an exponent.
Hook lengths and shifted parts of partitionsJul 11 2008Some conjectures on partition hook lengths, recently stated by the author, have been proved and generalized by Stanley, who also needed a formula by Andrews, Goulden and Jackson on symmetric functions to complete his derivation. Another identity on symmetric ... More
Superfluidity of Bose-Einstein Condensate in An Optical Lattice: Landau-Zener Tunneling and Dynamical InstabilityJun 16 2003Jul 02 2003Superflow of Bose-Einstein condensate in an optical lattice is represented by a Bloch wave, a plane wave with periodic modulation of the amplitude. We review the theoretical results on the interaction effects in the energy dispersion of the Bloch waves ... More
Landau and Dynamical Instabilities of the Superflow of Bose-Einstein Condensates in Optical LatticesSep 28 2000Apr 06 2001The superfluidity of Bose-Einstein condensates in optical lattices are investigated. Apart from the usual Landau instability which occurs when a BEC flows faster than the speed of sound, the BEC can also suffer a dynamical instability, resulting in period ... More
On Difference-of-SOS and Difference-of-Convex-SOS Decompositions for PolynomialsMar 27 2018Sep 15 2018In this paper, we are interested in difference-of-convex (DC) decompositions of polynomials. We investigate polynomial decomposition techniques for reformulating any multivariate polynomial into difference-of-sums-of-squares (DSOS) and difference-of-convex-sums-of-squares ... More
Maximizing Matching in Double-sided AuctionsFeb 11 2013In this paper, we introduce a novel, non-recursive, maximal matching algorithm for double auctions, which aims to maximize the amount of commodities to be traded. It differs from the usual equilibrium matching, which clears a market at the equilibrium ... More
$(1^3+1)(2^3+1)\cdots(n^3+1)$ is not a cubeDec 24 2016For a positive integer $n,$ define $$C_n=\prod_{k=1}^n(k^3+1).$$ In this paper we prove that there are no cubes in the integer sequence $C_n,~n=1,2,\cdots.$
The role of Berry phase in the spectrum of order parameter dynamics: a new perspective on Haldane's conjecture on antiferromagnetic spin chainsMar 17 2000We formulate the dynamics of local order parameters by extending the recently developed adiabatic spinwave theory involving the Berry curvature, and derive a formula showing explicitly the role of the Berry phase in determining the spectral form of the ... More
Hardy-Littlewood-Sobolev Type Inequality and Stein-Wiess Type Inequality on Carnot GroupsMar 21 2013A Stein-Weiss type inequality on Carnot groups is established by proving the boundedness of an integral operator and the Hardy-Littlewood-Sobolev type inequality on Carnot groups is also derived.
Existence of optimizers of the Stein-Weiss inequalities on Carnot groupsFeb 28 2014This paper proves existence of optimizers of the Stein-Weiss inequalities on Carnot groups under some conditions. The adjustment of Lions' concentration compactness principles to Carnot groups plays an important role in our proof. Unlike known treatment ... More
Attractive electron-electron interaction induced by geometric phase in a Bloch bandJan 24 2006Nov 21 2006We investigate electron pairing in the presence of the Berry curvature field that ubiquitously exists in ferromagnetic metals with spin-orbit coupling. We show that a sufficiently strong Berry curvature field on the Fermi surface can transform a repulsive ... More
Hankel continued fraction and its applicationsJun 06 2014The Hankel determinants of a given power series $f$ can be evaluated by using the Jacobi continued fraction expansion of $f$. However the existence of the Jacobi continued fraction needs that all Hankel determinants of $f$ are nonzero. We introduce {\it ... More
Discovering hook length formulas by expansion techniqueMay 16 2008We introduce the hook length expansion technique and explain how to discover old and new hook length formulas for partitions and plane trees. The new hook length formulas for trees obtained by our method can be proved rather easily, whereas those for ... More
The effect of the incident relative phase on the four-wave mixing field and the electromagnetically induced transparencyJun 08 2004Aug 11 2004In a Lambda-type system employing a two-photon pump field, a four-wave mixing field can be generated simultaneously and hence a closed-loop system forms. We study theoretically on the effect of the relative phase between the two incident fields on the ... More
A tracially AF algebra which is not $\mathcal Z$-absorbingFeb 08 2019Feb 28 2019We show that there is a simple separable unital (non-nuclear) tracially AF algebra $A$ which does not absorb the Jiang-Su algebra $\mathcal Z$ tensorially, i.e. $A \ncong A\otimes\mathcal Z$.
Double-tip STM for Surface AnalysisMay 13 1994Dec 26 1994We explore the possibility of using a double-tip STM to probe the single electron Green function of a sample surface, and describe a few important applications: (1) Probing constant energy surfaces in $\k$-space by ballistic transport; (2) Measuring scattering ... More
Coordinate shift in the semiclassical Boltzmann equation and the anomalous Hall effectNov 12 2005Jan 27 2006We propose a gauge invariant expression for the side jump associated with scattering between particular Bloch states. Our expression for the side jump follows from the Born series expansion for the scattering T-matrix in powers of the strength of the ... More
Waltzing of a Helium Pair in Tungsten: Migration Barrier and Trajectory Revealed from First-PrinciplesApr 18 2014Despite well documented first-principles theoretical determination of the low migration energy (0.06 eV) of a single He in tungsten, fully quantum mechanical calculations on the migration of a He pair still present a challenge due to the complexity of ... More
Significant contribution of As 4p orbitals to the low-lying electronic structure of 112-type iron-based superconductor Ca0.9La0.1FeAs2Nov 20 2014We report a systematic polarization-dependent angle-resolved photoemission spectroscopy study of the three-dimensional electronic structure of the recently discovered 112-type iron-based superconductor Ca1-xLaxFeAs2 (x = 0.1). Besides the commonly reported ... More
Nonsaturating large magnetoresistance in the high carrier density nonsymmorphic metal CrPMar 14 2019The band structure of high carrier density metal CrP features an interesting crossing at the Y point of the Brillouin zone. The crossing, which is protected by the nonsymmorphic symmetry of the space group, results in a hybrid, semi-Dirac-like energy-momentum ... More
Weak Field Phase Diagram for an Integer Quantum Hall LiquidApr 04 1995We study the localization properties in the transition from a two-dimensional electron gas at zero magnetic field into an integer quantum Hall (QH) liquid. By carrying out a direct calculation of the localization length for a finite size sample using ... More
Signature of strong spin-orbital coupling in the large non-saturating magnetoresistance material WTe2Mar 04 2015We report the detailed electronic structure of WTe$_2$ by high resolution angle-resolved photoemission spectroscopy. Unlike the simple one electron plus one hole pocket type of Fermi surface topology reported before, we resolved a rather complicated Fermi ... More
Bulk and surface electronic structure of trigonal structured PtBi2 studied by angle-resolved photoemission spectroscopyJul 12 2016Jul 20 2016PtBi2 with a layered trigonal crystal structure was recently reported to exhibit an unconventional large linear magnetoresistance, while the mechanism involved is still elusive. Using high resolution angle-resolved photoemission spectroscopy, we present ... More
An Investigation Report on Auction Mechanism DesignApr 08 2009Apr 14 2009Auctions are markets with strict regulations governing the information available to traders in the market and the possible actions they can take. Since well designed auctions achieve desirable economic outcomes, they have been widely used in solving real-world ... More
Higher gradients estimates in Morrey spaces for weak solutions to linear ultraparabolic equationsApr 25 2014The aim of this paper is to consider the linear ultraparabolic equation with bounded and VMO coefficients $a_{ij} (z)$. Assume that the operator $L_0$ obtained by freezing the coefficients $a_{ij}(z)$ at any point ${z_0} \in {\mathbb{R}^{N + 1}}$ is hypoelliptic. ... More
A robust adaptive-to-model enhancement test for parametric single-index modelsOct 12 2015In the research on checking whether the underlying model is of parametric single-index structure with outliers in observations, the purpose of this paper is two-fold. First, a test that is robust against outliers is suggested. The Hampel's second-order ... More
Yet another generalization of Postnikov's hook length formula for binary treesApr 27 2008We discover another one-parameter generalization of Postnikov's hook length formula for binary trees. The particularity of our formula is that the hook length $h_v$ appears as an exponent. As an application, we derive another simple hook length formula ... More
Anisotropic two-gap superconductivity and the absence of a Pauli paramagnetic limit in single-crystalline LaO$_{0.5}$F$_{0.5}$BiS$_2$Oct 30 2017Mar 20 2018Ambient-pressure-grown LaO$_{0.5}$F$_{0.5}$BiS$_2$ with a superconducting transition temperature $T_{c}\sim$3K possesses a highly anisotropic normal state. By a series of electrical resistivity measurements with a magnetic field direction varying between ... More
Measurements of a fast nuclear spin dynamics in a single InAs quantum dot with positively charged excitonJan 05 2012By using highly time-resolved spectroscopy with an alternative {\sigma}+/{\sigma} - laser pulse modulation technique, we are able to measure the fast buildup and decay times of the dynamical nuclear spin polarization (DNSP) at 5 K for a single InAs quantum ... More
Band dependent inter-layer $f$-electron hybridization in CeRhIn$_5$Jan 23 2018A key issue in heavy fermion research is how subtle changes in the hybridization between the 4$f$ (5$f$) and conduction electrons can result in fundamentally different ground states. CeRhIn$_5$ stands out as a particularly notable example: replacing Rh ... More
Observation of in-gap surface states in the Kondo insulator SmB6 by photoemissionJun 24 2013Kondo insulators (KIs) are strongly correlated materials in which the interactions between 4f and conduction electrons lead to a hybridization gap opening at low temperature 1-2. SmB6 is a typical KI, but its resistivity does not diverge at low temperatures, ... More
Temperature dependence of electron-spin relaxation in a single InAs quantum dot at zero applied magnetic fieldJan 05 2012The temperature-dependent electron spin relaxation of positively charged excitons in a single InAs quantum dot (QD) was measured by time-resolved photoluminescence spectroscopy at zero applied magnetic fields. The experimental results show that the electron-spin ... More
Direct observation of how the heavy fermion state develops in CeCoIn5Oct 21 2016Heavy fermion materials gain high electronic masses and expand Fermi surfaces when the high-temperature localized f electrons become itinerant and hybridize with the conduction band at low temperatures. However, despite the common application of this ... More
A breakthrough in Speech emotion recognition using Deep Retinal Convolution Neural NetworksJul 12 2017Speech emotion recognition (SER) is to study the formation and change of speaker's emotional state from the speech signal perspective, so as to make the interaction between human and computer more intelligent. SER is a challenging task that has encountered ... More
Difference operators for partitions and some applicationsAug 04 2015Jan 18 2018Motivated by the Nekrasov-Okounkov formula on hook lengths, the first author conjectured that the Plancherel average of the $2k$-th power sum of hook lengths of partitions with size $n$ is always a polynomial of $n$ for any $k\in \mathbb{N}$. This conjecture ... More
On $t$-extensions of the Hankel determinants of certain automatic sequencesJun 06 2014In 1998, Allouche, Peyri\`ere, Wen and Wen considered the Thue--Morse sequence, and proved that all the Hankel determinants of the period-doubling sequence are odd integral numbers. We speak of $t$-extension when the entries along the diagonal in the ... More
Multivariable Tangent and Secant q-derivative PolynomialsApr 09 2013The derivative polynomials introduced by Knuth and Buckholtz in their calculations of the tangent and secant numbers are extended to a multivariable $q$--environment. The $n$-th $q$-derivatives of the classical $q$-tangent and $q$-secant are each given ... More
Some useful theorems for asymptotic formulas and their applications to skew plane partitions and cylindric partitionsJul 16 2017Inspired by the works of Dewar, Murty and Kot\v{e}\v{s}ovec, we establish some useful theorems for asymptotic formulas. As an application, we obtain asymptotic formulas for the numbers of skew plane partitions and cylindric partitions. We prove that the ... More
A basis for the right quantum algebra and the "1=q" principleMar 19 2006We construct a basis for the right quantum algebra introduced by Garoufalidis, Le and Zeilberger and give a method making it possible to go from an algebra submitted to commutation relations (without the variable q) to the right quantum algebra by means ... More
On the classification of simple amenable C*-algebras with finite decomposition rankJul 28 2015Feb 02 2016Let $A$ be a unital simple separable C*-algebra satisfying the UCT. Assume that $\mathrm{dr}(A)<+\infty$, $A$ is Jiang-Su stable, and $\mathrm{K}_0(A)\otimes \mathbb{Q}\cong \mathbb{Q}$. Then $A$ is an ASH algebra (indeed, $A$ is a rationally AH algebra). ... More
Explicit evaluations of the Hankel determinants of a Thue--Morse-like sequenceJun 06 2014We obtain the explicit evaluations of the Hankel determinants of the formal power series $\prod_{k\geq 0}(1+Jx^{3^{k}})$ where $J={(\sqrt{-3}-1)}/2$, and prove that the sequence of Hankel determinants is an aperiodic automatic sequence taking value in ... More
Fix-Mahonian Calculus III; a Quadruple DistributionMar 15 2007A four-variable distribution on permutations is derived, with two dual combinatorial interpretations. The first one includes the number of fixed points "fix", the second the so-called "pix" statistic. This shows that the duality between derangements and ... More
Fix-Mahonian Calculus, I: two transformationsMar 04 2007We construct two bijections of the symmetric group S_n onto itself that enable us to show that three new three-variable statistics are equidistributed with classical statistics involving the number of fixed points. The first one is equidistributed with ... More
Permutations with Extremal number of Fixed PointsJun 12 2007Jun 22 2007We extend Stanley's work on alternating permutations with extremal number of fixed points in two directions: first, alternating permutations are replaced by permutations with a prescribed descent set; second, instead of simply counting permutations we ... More
Specializations and Extensions of the quantum MacMahon Master TheoremMar 19 2006We study some specializations and extensions of the quantum version of the MacMahon Master Theorem derived by Garoufalidis, Le and Zeilberger. In particular, we obtain a (t,q)-analogue for the Cartier-Foata noncommutative version and a semi-strong (t,q)-analogue ... More
Pairing-energy coefficients of neutron-rich fragments in spallation reactionsJan 06 2018The ratio of pairing-energy coefficient to temperature ($a_{p}/T$) of neutron-rich fragments produced in spallation reactions has been investigated by adopting an isobaric yield ratio method deduced in the framework of a modified Fisher model. A series ... More
A combinatorial proof of the non-vanishing of Hankel determinants of the Thue--Morse sequenceJun 06 2014In 1998, Allouche, Peyri\`ere, Wen and Wen established that the Hankel determinants associated with the Thue--Morse sequence on $\{-1, 1\}$ are always nonzero. Their proof depends on a set of sixteen recurrence relations. We present an alternative, purely ... More
Tree Calculus for Bivariable Difference EquationsApr 09 2013Following Poupard's study of strictly ordered binary trees with respect to two parameters, namely, "end of minimal chain" and "parent of maximum leaf" a true Tree Calculus is being developed to solve a partial difference equation system and then make ... More
Andre Permutation Calculus; a Twin Seidel Matrix SequenceJan 18 2016Entringer numbers occur in the Andr\'e permutation combinatorial set-up under several forms. This leads to the construction of a matrix-analog refinement of the tangent (resp. secant) numbers. Furthermore, closed expressions for the three-variate exponential ... More
A New Proof of the Garoufalidis-Le-Zeilberger Quantum MacMahon Master TheoremMar 19 2006We propose a new proof of the quantum version of MacMahon's Master Theorem, established by Garoufalidis, Le and Zeilberger.
The C*-algebra of a minimal homeomorphism of zero mean dimensionJun 09 2014Mar 08 2016Let $X$ be an infinite compact metrizable space, and let $\sigma: X\to X$ be a minimal homeomorphism. Suppose that $(X, \sigma)$ has zero mean topological dimension. The associated C*-algebra $A=\mathrm{C}(X)\rtimes_\sigma\mathbb Z$ is shown to absorb ... More
Skew ribbon plane partitions: calculus and asymptoticsJul 18 2017Plane partitions have been widely studied in Mathematics since MacMahon. See, for example, the works by Andrews, Macdonald, Stanley, Sagan and Krattenthaler. The Schur process approach, introduced by Okounkov and Reshetikhin, and further developed by ... More
Computer assisted proof for Apwenian sequences related to Hankel determinantsJan 18 2016An infinite $\pm 1$-sequence is called {\it Apwenian} if its Hankel determinant of order $n$ divided by $2^{n-1}$ is an odd number for every positive integer $n$. In 1998, Allouche, Peyri\`ere, Wen and Wen discovered and proved that the Thue--Morse sequence ... More
New hook-content formulas for strict partitionsNov 09 2015Dec 13 2016We introduce the difference operator for functions defined on strict partitions and prove a polynomiality property for a summation involving the hook length and content statistics. As an application, several new hook-content formulas for strict partitions ... More