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Generation and distribution of high-dimensional frequency-entangled quditsMar 25 2016Mar 31 2016We demonstrate a novel scheme to generate frequency-entangled qudits with dimension number higher than 10 and to distribute them over optical fibers of 15 km in total length. This scheme combines the technique of spectral engineering of biphotons generated ... More

Modified E91 protocol demonstration with hybrid entanglement photon sourceJan 23 2015We report on an experimental demonstration of the modified Ekert 91 protocol of quantum key distribution using a hybrid entanglement source with two different degrees of freedoms, a 1550 nm time-bin qubit and 810 nm polarization qubit. The violation of ... More

Superconducting nanowire single photon detectors for quantum information and communicationsMar 01 2010Superconducting nanowire single photon detectors (SNSPD or SSPD) are highly promising devices in the growing field of quantum information and communications technology. We have developed a practical SSPD system with our superconducting thin films and ... More

Low-Filling-Factor Superconducting Single Photon Detector with High System Detection EfficiencyMay 13 2013Nov 15 2013We designed, fabricated, and measured superconducting nanowire single-photon detectors (SSPDs) with low filling factor which achieve high system detection efficiency (SDE) and counting rate simultaneously. Numerical simulation reveals that high optical ... More

Two-photon Quantum Interference and Entanglement at 2 μmJun 05 2019Quantum-enhanced optical systems operating within the 2 {\mu}m spectral region have the potential to revolutionise emerging applications in communications, sensing and metrology. However, to date, sources of entangled photons have been realised mainly ... More

Compactly packaged superconducting nanowire single-photon detector with an optical cavity for multichannel systemFeb 28 2010We developed superconducting nanowire single-photon detectors with an optical cavity (OC-SNSPDs) for multichannel systems. For efficient coupling, the devices were installed in compact fiber-coupled packages after their substrate thickness was reduced ... More

Crosstalk-free operation of multi-element SSPD array integrated with SFQ circuit in a 0.1 Watt GM cryocoolerJul 17 2012We demonstrate the successful operation of a multi-element superconducting nanowire single-photon detector (SSPD) array integrated with a single-flux-quantum (SFQ) readout circuit in a compact 0.1 W Gifford-McMahon cryocooler. A time-resolved readout ... More

Stable, high-performance operation of a fiber-coupled superconducting nanowire avalanche photon detectorJan 25 2017We present a stable and high-performance fiber-coupled NbTiN superconducting nanowire avalanche photon detector (SNAP). We demonstrate afterpulse-free operation in serially connected two SNAPs (SC-2SNAP), even in the absence of a choke inductor, achieving ... More

Development of SNSPD System with Gifford-McMahon CryocoolerMar 02 2010A superconducting nanowire single photon detector (SNSPD) system for telecommunication wavelength using a GM cryocooler was developed and its performance was verified. The cryocooler based SNSPD system can operate continuously with a 100 V AC power supply ... More

64-pixel NbTiN superconducting nanowire single-photon detector array for spatially resolved photon detectionJan 31 2014We present the characterization of two-dimensionally arranged 64-pixel NbTiN superconducting nanowire single-photon detector array for spatially resolved photon detection. NbTiN films deposited on thermally oxidized Si substrates enabled the high-yield ... More

High performance fiber-coupled NbTiN superconducting nanowire single photon detectors with Gifford-McMahon cryocoolerMar 26 2013Apr 11 2013We present high performance fiber-coupled niobium titanium nitride superconducting nanowire single photon detectors fabricated on thermally oxidized silicon substrates. The best device showed a system detection efficiency (DE) of 74%, dark count rate ... More

Photon level crosstalk between parallel fibers installed in urban areaAug 05 2010We estimate the channel characteristics of field-installed dark fibers at single photon levels for quantum key distribution (QKD). Measured fibers are telecom single-mode dark fibers over 45 km connecting a center and suburbs of Tokyo. Their total losses ... More

Multi-channel SNSPD system with high detection efficiency at telecommunication wavelengthApr 01 2010We developed a four-channel superconducting nanowire single-photon detector system based on a Gifford-McMahon cryocooler. All channels showed a system detection efficiency (at a 100 Hz dark-count rate) higher than 16% at 1550 nm wavelength, and the best ... More

Toroidal and level 0 U'_q(\hat{sl_{n+1}}) actions on U_q(\hat{gl_{n+1}}) modulesAug 05 1998(1) Utilizing a Braid group action on a completion of U_q(\hat{sl_{n+1}}), an algebra homomorphism from the toroidal algebra U_q(sl_{n+1,tor}) (n\ge 2) with fixed parameter to a completion of U_q(\hat{gl_{n+1}}) is obtained. (2) The toroidal actions by ... More

Optimal conditions for Bell test using spontaneous parametric down-conversion sourcesAug 25 2018We theoretically and experimentally investigate the optimal conditions for the Bell experiment using spontaneous parametric down conversion (SPDC) sources. In theory, we show that relatively large average photon number (typically $\sim$0.5) is desirable ... More

Frequency-multiplexed singly-resonant photon pairs from a quadratic nonlinear optical waveguide resonatorApr 30 2019We demonstrate a frequency multiplexed photon pair generation based on a quadratic nonlinear optical waveguide inside a cavity which confines only signal photons without confining idler photons and the pump light. We monolithically constructed the photon ... More

Temperature Dependent Performances of Superconducting Nanowire Single-Photon Detectors in an Ultralow-Temperature RegionSep 21 2010We present the performances of a superconducting nanowire single-photon detector (SNSPD) in an ultralow-temperature region from 16 mK to 4 K. The system detection efficiency of the SNSPD showed saturation in the bias-current and temperature dependences, ... More

Finite current stationary states of random walks on one-dimensional lattices with aperiodic disorderApr 12 2016Stationary states of random walks with finite induced drift velocity on one-dimensional lattices with aperiodic disorder are investigated by scaling analysis. Three aperiodic sequences, the Thue-Morse (TM), the paperfolding (PF), and the Rudin-Shapiro ... More

Inevitable Irreversibility Generated by the Glass Transition of the Binary Lattice Gas ModelAug 17 2001We numerically investigate the thermodynamic properties of the glass state. As the object of our study, we employ a binary lattice gas model. Through Monte Carlo simulations, we find that this model actually experiences a glass transition. We introduce ... More

Extended force density method and its expressionsApr 19 2011The objective of this work can be divided into two parts. The first one is to propose an extension of the force density method (FDM)(H.J. Schek, 1974), a form-finding method for prestressed cable-net structures. The second one is to present a review of ... More

Three-term Method and Dual Estimate on Static Problems of Continuum BodiesAug 05 2011Aug 13 2011This work aims to provide standard formulations for direct minimization approaches on various types of static problems of continuum mechanics. Particularly, form-finding problems of tension structures are discussed in the first half and the large deformation ... More

Stationary state of a zero-range process corresponding to multifractal one-particle distributionSep 12 2016We investigate a zero-range process where the underlying one-particle stationary distribution has multifractality. The multiparticle stationary probability measure can be written in a factorized form. If the number of the particles is sufficiently large, ... More

Nonclasscial interference between independent intrinsically pure single photons at telecom wavelengthMar 12 2013Jul 24 2013We demonstrate a Hong-Ou-Mandel interference between two independent, intrinsically pure, heralded single photons from spontaneous parametric down conversion (SPDC) at telecom wavelength. A visibility of $85.5\pm8.3%$ was achieved without using any bandpass ... More

Scaling analysis of stationary probability distributions of random walks on one-dimensional lattices with aperiodic disorderMay 19 2014Stationary probability distributions of one-dimensional random walks on lattices with aperiodic disorder are investigated. The pattern of the distribution is closely related to the diffusional behavior, which depends on the wandering exponent $\Omega$ ... More

Frequency-domain Hong-Ou-Mandel interferenceJan 05 2016Hong-Ou-Mandel (HOM) interference unveils a distinct behavior of identical particles which cannot be distinguished from each other. Especially for bosons, two separated identical particles passing through a beamsplitter always go together into one of ... More

Mach-Zehnder interferometer using frequency-domain beamsplitterMar 23 2017We demonstrated the first-order interference between coherent light at 1580 nm and 795 nm by using frequency-domain Mach-Zehnder interferometer (MZI). The MZI is implemented by two frequency-domain BSs based on a second-order nonlinear optical effect ... More

Heralded single excitation of atomic ensemble via solid-state-based telecom photon detectionJul 06 2016Telecom photonic quantum networks with matter quantum systems enable a rich variety of applications, such as a long distance quantum cryptography and one-way quantum computing. Preparation of a heralded single excitation (HSE) in an atomic ensemble by ... More

Efficient detection of a highly bright photon source using superconducting nanowire single photon detectorsSep 05 2013May 06 2014We investigate the detection of an ultra-bright single-photon source using highly efficient superconducting nanowire single-photon detectors (SNSPDs) at telecom wavelengths. Both the single-photon source and the detectors are characterized in detail. ... More

High-fidelity entanglement swapping and generation of three-qubit GHZ state using asynchronous telecom photon pair sourcesDec 22 2016We experimentally demonstrate a high-fidelity entanglement swapping and a generation of the Greenberger-Horne-Zeilinger~(GHZ) state using polarization-entangled photon pairs at telecommunication wavelength produced by spontaneous parametric down conversion ... More

Countermeasure against tailored bright illumination attack for DPS-QKDAug 10 2013We propose a countermeasure against the so-call tailored bright illumination attacl dor Differential-Phase-Shift QKD (DPS-QKD). By Monitoring a rate of coincidence detection at a pair of superconducting nanowire single photon detectors (SSPDs) which is ... More

Nanoantenna enhancement for telecom-wavelength superconducting single photon detectorsJan 14 2015Superconducting nanowire single photon detectors are rapidly emerging as a key infrared photon-counting technology. Two front-side-coupled silver dipole nanoantennas, simulated to have resonances at 1480 nm and 1525 nm, were fabricated in a two-step process. ... More

Pulsed Sagnac polarization-entangled photon source with a PPKTP crystal at telecom wavelengthNov 14 2013May 06 2014We demonstrate pulsed polarization-entangled photons generated from a periodically poled $\mathrm{KTiOPO_4}$ (PPKTP) crystal in a Sagnac interferometer configuration at telecom wavelength. Since the group-velocity-matching (GVM) condition is satisfied, ... More

Multifractal Distribution of Dendrite on One-dimensional SupportMar 04 2013We apply multifractal analysis to an experimentally obtained quasi-two-dimensional crystal with fourfold symmetry, in order to characterize the sidebranch structure of a dendritic pattern. In our analysis, the stem of the dendritic pattern is regarded ... More

Matter-Wave Bright Solitons with a Finite Background in Spinor Bose-Einstein CondensatesApr 01 2007We investigate dynamical properties of bright solitons with a finite background in the F=1 spinor Bose-Einstein condensate (BEC), based on an integrable spinor model which is equivalent to the matrix nonlinear Schr\"{o}dinger equation with a self-focusing ... More

Asymptotic form of two-point correlation function of the XXZ spin chainFeb 15 2000May 03 2000Correlation functions of the XXZ spin chain in the critical regime is studied at zero-temperature. They are exactly represented in the Fredholm determinant form and are related with an operator-valued Riemann-Hilbert problem. Analyzing this problem we ... More

Operator-valued Riemann-Hilbert problem for correlation functions of the XXZ spin chainOct 30 1999Dec 16 1999The generating functional of correlation functions for the XXZ spin chain is considered in the thermodynamic limit. We derive a system of integro-difference equations that prescribe this functional. On the basis of this system we establish the operator-valued ... More

Gaudin Hypothesis for the XYZ Spin ChainAug 24 1999Nov 02 1999The XYZ spin chain is considered in the framework of the generalized algebraic Bethe ansatz developed by Takhtajan and Faddeev. The sum of norms of the Bethe vectors is computed and expressed in the form of a Jacobian. This result corresponds to the Gaudin ... More

Finite Size Formula in the XYZ Spin ChainSep 09 1998The XYZ spin chain with boundaries is studied. We construct the vacuum state by the vertex operators in the level one modules of the elliptic algebra, and compact it through a geometric symmetry of the model called the turning symmetry. From this simplified ... More

Rodrigues Formula for Hi-Jack Symmetric Polynomials Associated with the Quantum Calogero ModelSep 04 1996The Hi-Jack symmetric polynomials, which are associated with the simultaneous eigenstates for the first and second conserved operators of the quantum Calogero model, are studied. Using the algebraic properties of the Dunkl operators for the model, we ... More

Partition Function for a 1-D delta-function Bose GasDec 13 2002The N-particle partition function of a one-dimensional $\delta$-function bose gas is calculated explicitly using only the periodic boundary condition (the Bethe ansatz equation). The N-particles cluster integrals are shown to be the same as those by the ... More

RSK type correspondence of Pictures and Littlewood-Richardson CrystalsMay 31 2010We present a Robinson-Schensted-Knuth type one-to-one correspondence between the set of pictures and the set of pairs of Littlewood-Richardson crystals.

L operators and Drinfeld's generatorsMay 26 1997Utilizing the multiplicative formula of universal R matrix, the correspondence between the L operators and Drinfeld's generators is explicitly calculated for quantum group U_q(g) with g=A_l^{(1)}, B_l^{(1)}, C_l^{(1)}, D_l^{(1)}.

Rodrigues Formula for the Nonsymmetric Multivariable Hermite PolynomialMay 13 1999Applying a method developed by Takamura and Takano for the nonsymmetric Jack polynomial, we present the Rodrigues formula for the nonsymmetric multivariable Hermite polynomial.

Effective QCD Partition Function in Sectors with Non-Zero Topological Charge and Itzykson-Zuber Type IntegralApr 07 1998It was conjectured by Jackson et.al. that the finite volume effective partition function of QCD with the topological charge $M-N$ coincides with the Itzyskon-Zuber type integral for $M\times N$ rectangular matrices. In the present article we give a proof ... More

Multipartite Entanglement and HyperdeterminantsDec 27 2002We classify multipartite entanglement in a unified manner, focusing on a duality between the set of separable states and that of entangled states. Hyperdeterminants, derived from the duality, are natural generalizations of entanglement measures, the concurrence, ... More

A note on inverse-square exchange modelsJun 19 1995Jul 12 1995The su(1$|$1) symmetric version of the Haldane-Shastry spin chain is diagonalized by means of a linear transformation. The same transformation applied to the original su(2) model yields simple expressions for the Hamiltonian and the generators of the ... More

A new recurrence formula for generic exceptional orthogonal polynomialsOct 01 2014A new recurrence relation for exceptional orthogonal polynomials is proposed, which holds for type 1, 2 and 3. As concrete examples, the recurrence relations are given for Xj-Hermite, Laguerre and Jacobi polynomials in j = 1,2 case.

Pictures and Littlewood-Richardson crystalsApr 10 2009May 20 2009We shall describe the one-to-one correspondence between the set of pictures and the set of Littlewood-Richardson crystals.

Direct Calculation of Thermodynamic Quantities for Heisenberg ModelDec 13 2002The XXX Heisenberg model is studied at finite temperature. The free energy is derived without recourse to Thermal Bethe Ansatz method and Quantum Transfer Matrix method. The result perfectly agrees with the free energy derived by Thermal Bethe Ansatz ... More

GOTHIC: Gravitational oct-tree code accelerated by hierarchical time step controllingOct 24 2016The tree method is a widely implemented algorithm for collisionless $N$-body simulations in astrophysics well suited for GPU(s). Adopting hierarchical time stepping can accelerate $N$-body simulations; however, it is infrequently implemented and its potential ... More

Integrable Boundary Conditions for the One-Dimensional Hubbard ModelAug 01 1997We discuss the integrable boundary conditions for the one-dimensional (1D) Hubbard Model in the framework of the Quantum Inverse Scattering Method (QISM). We use the fermionic R-matrix proposed by Olmedilla et al. to treat the twisted periodic boundary ... More

Geometric Strategy for the Optimal Quantum SearchSep 21 2001We explore quantum search from the geometric viewpoint of a complex projective space $CP$, a space of rays. First, we show that the optimal quantum search can be geometrically identified with the shortest path along the geodesic joining a target state, ... More

On the Additional Symmetry; Many-Body Problem Related to the KP HierarchyFeb 04 1994Nonlinear integrable equations, such as the KdV equation, the Boussinesq equation and the KP equation, have the close relation with many-body problem. The solutions of such equations are the same as the restricted flows of the classical Calogero model, ... More

Early Evolution of Bird-Type Language without Grammar: Duplication and MutationOct 22 2016Using a series of computer simulations we have demonstrated a scenario of the early evolution of the bird-type primitive language. We do not assume wise agents who can use a grammar and manage an evolution without a grammar. Duplication and mutation of ... More

Second sound in 2D Bose gas: from the weakly interacting to the strongly interacting regimeDec 13 2017Using Landau's theory of two-fluid hydrodynamics, we investigate first and second sound propagating in a two-dimensional Bose gas. We study the temperature and interaction dependence of both sound modes and show that their behaviour exhibits a deep qualitative ... More

Admissible Pictures and Littlewood-Richardson CrystalsAug 17 2009We present a one-to-one correspondence between the set of admissible pictures and the Littlewood-Richardson crystals. As a simple consequence, we shall show that the set of pictures does not depend on the choice of admissible orders.

Correlation Function of Asymmetric Simple Exclusion Process with Open BoundariesOct 01 2004We investigate the correlation functions of the one-dimensional Asymmetric Simple Exclusion Process (ASEP) with open boundaries. The conditions for the boundaries are made most general. The correlation function is expressed in a multifold integral whose ... More

Universal Transport Properties of Disordered Quantum WiresMar 28 2002For disordered quantum wires which belong to all ten universality classes, the universal quantities of transport properties are obtained through DMPK approach. Calculated are the universal parts of one- and two-point correlation functions for probability ... More

Bosonic and Fermionic Eigenstates for Generalized Sutherland ModelsAug 29 2000We construct bosonic and fermionic eigenstates for the generalized Sutherland models associated with arbitrary reduced root systems respectively, through W-symmetrization and W-anti-symmetrization of Heckman-Opdam's nonsymmetric Jacobi polynomials. Square ... More

Complete integrability of derivative nonlinear Schrödinger-type equationsAug 11 1999We study matrix generalizations of derivative nonlinear Schr\"{o}dinger-type equations, which were shown by Olver and Sokolov to possess a higher symmetry. We prove that two of them are `C-integrable' and the rest of them are `S-integrable' in Calogero's ... More

Multi-Field Integrable Systems Related to WKI-Type Eigenvalue ProblemsJul 22 1999Higher flows of the Heisenberg ferromagnet equation and the Wadati-Konno-Ichikawa equation are generalized into multi-component systems on the basis of the Lax formulation. It is shown that there is a correspondence between the multi-component systems ... More

The Calogero Model: Integrable Structures and Orthogonal BasisJun 16 1997Integrability, algebraic structures and orthogonal basis of the Calogero model are studied by the quantum Lax and Dunkl operator formulations. The commutator algebra among operators including conserved operators and creation-annihilation operators has ... More

Matrix Models of Two-dimensional Gravity and Discrete Toda TheoryMay 23 1996Recursion relations for orthogonal polynominals, arising in the study of the one-matrix model of two-dimensional gravity, are shown to be equvalent to the equations of the Toda-chain hierarchy supplemented by additional Virasoro constraints. This is the ... More

Spontaneous Magnetization in the Finite XXZ Spin Chain with BoundariesJul 28 1998Sep 09 1998The finite XXZ spin chain with boundaries is studied. We derive the transfer matrix from the q-difference equation discovered by Cherednik and construct its eigenstates by the vertex operator approach. We point out that the eigenstates with no magnetic ... More

Correlation Functions of Finite XXZ model with BoundariesJan 28 1998Mar 13 1998The finite XXZ model with boundaries is considered. We use the Matrix Product Ansatz (MPA), which was originally developed in the studies on the asymmetric simple exclusion process and the quantum antiferromagnetic spin chain. The MPA tells that the eigenstate ... More

Iterative conformal mapping approach to diffusion-limited aggregation with surface tension effectMar 04 2013We present a simple method for incorporating the surface tension effect into an iterative conformal mapping model of two-dimensional diffusion-limited aggregation. A curvature-dependent growth probability is introduced and the curvature is given by utilizing ... More

Effects of Bridge Functions on Radial Distribution Functions of Liquid WaterMay 22 2014In this report the radial distribution functions (RDFs) of liquid water are calculated on the basis of the classical density functional theory combined with the reference interaction site model for molecular liquids. The bridge functions, which are neglected ... More

High-fidelity conversion of photonic quantum information to telecommunication wavelength with superconducting single-photon detectorsJul 06 2012We experimentally demonstrate a high-fidelity visible-to-telecommunication wavelength conversion of a photon by using a solid-state-based difference frequency generation. In the experiment, one half of a pico-second visible entangled photon pair at 780 ... More

A low-noise frequency down-conversion to the telecommunication band for a quantum communication based on NV centers in diamondFeb 12 2014We demonstrate a low-noise frequency down-conversion of photons at 637 nm to the telecommunication band at 1587 nm by the difference frequency generation in a periodically-poled lithium niobate. An internal conversion efficiency of the converter is estimated ... More

Detection-dependent six-photon NOON state interferenceJul 04 2016NOON state interference (NOON-SI) is a powerful tool to improve the phase sensing precision, and can play an important role in quantum sensing and quantum imaging. However, most of the previous NOON-SI experiments only investigated the center part of ... More

Heralded amplification of nonlocality via entanglement swapping for long-distance device-independent quantum key distributionApr 12 2019May 07 2019To realize the practical implementation of device-independent quantum key distribution~(DIQKD), the main difficulty is that its security relies on the detection-loophole-free violation of the Clauser-Horne-Shimony-Holt~(CHSH) inequality, i.e. the CHSH ... More

A high visibility Hong-Ou-Mandel interference via a time-resolved coincidence measurementAug 17 2016We report on the observation of a high visibility Hong-Ou-Mandel interference of two heralded photons emitted from a spontaneous parametric down conversion~(SPDC) pumped by continuous-wave~(cw) light. A non-degenerate photon pair at 1541~nm and 1580~nm ... More

Non-classical two-photon interference between independent telecom light pulses converted by difference-frequency generationApr 01 2013We experimentally demonstrated the Hong-Ou-Mandel (HOM) interference between two photons after visible-to-telecommunication wavelength conversion. In the experiment, we prepared a heralded single photon by using spontaneous parametric down-conversion ... More

Heralded amplification of nonlocality via entanglement swapping for long-distance device-independent quantum key distributionApr 12 2019To realize the practical implementation of device-independent quantum key distribution~(DIQKD), the main difficulty is that its security relies on the detection-loophole-free violation of the Clauser-Horne-Shimony-Holt~(CHSH) inequality, i.e. the CHSH ... More

Polarization insensitive frequency conversion for an atom-photon entanglement distribution via a telecom networkOct 25 2017Quantum network with a current telecom photonic infrastructure is deficient in quantum storages that keep arbitrary quantum state in sufficient time duration for a long-distance quantum communication with quantum repeater algorithms. Atomic quantum storages ... More

Observation of two output light pulses from a partial wavelength converter preserving phase of an input light at a single-photon levelSep 11 2013Nov 07 2013We experimentally demonstrate that both a converted and an unconverted light pulses after wavelength conversion with various conversion efficiencies preserve phase information of an input light at a single-photon level. In our experiment, we converted ... More

Nonlatching Superconducting Nanowire Single-Photon Detection with Quasi-Constant-Voltage BiasNov 07 2012Latching is a serious issue in superconducting nanowire single-photon detector (SNSPD) technology. By extensively studying the electrical transportation characteristics of SNSPD with different bias schemes, we conclude that latching is a result of the ... More

Spectrally resolved Hong-Ou-Mandel interference between independent sourcesJul 09 2015Hong-Ou-Mandel (HOM) interference between independent photon sources (HOMI-IPS) is the fundamental block for quantum information processing, such as quantum gate, Shor's algorithm, Boson sampling, etc. All the previous HOMI-IPS experiments were carried ... More

Efficient generation of twin photons at telecom wavelengths with 10 GHz repetition-rate tunable comb laserSep 10 2014Efficient generation and detection of indistinguishable twin photons are at the core of quantum information and communications technology (Q-ICT). These photons are conventionally generated by spontaneous parametric down conversion (SPDC), which is a ... More

Ultra fast quantum key distribution over a 97 km installed telecom fiber with wavelength-division multiplexing clock synchronizationMay 15 2008Jun 23 2008We demonstrated ultra fast BB84 quantum key distribution (QKD) transmission at 625 MHz clock rate through a 97 km field-installed fiber using practical clock synchronization based on wavelength-division multiplexing (WDM). We succeeded in over-one-hour ... More

Stochastic Energetics of Non-uniform Temperature SystemsOct 19 1998We propose an energetic interpretation ofstochastic processes described by Langevin equations with non-uniform temperature. In order to avoid It\^{o}-Stratonovich dilemma, we start with a Kramers equation, and derive a Fokker-Plank equation by the renormalization ... More

Growth rate distribution of NH_4Cl dendrite and its scaling structureMar 01 2013Scaling structure of the growth rate distribution on the interface of a dendritic pattern is investigated. The distribution is evaluated for an ${\rm NH_4Cl}$ quasi-two-dimensional crystal by numerically solving the Laplace equation with the boundary ... More

Exact Analysis of Delta-Function Attractive Fermions and Repulsive Bosons in One-DimensionMar 02 2005The Gaudin integral equation for the ground state of a one-dimensional delta-function attractive spin-1/2 fermions is solved in the form of power series. The first few terms of the asymptotic expansions for both strong and weak coupling cases are calculated ... More

A direct calculation of the free energy from the Bethe ansatz equation for the Heisenberg modelDec 13 2002Thermodynamics of the XXX Heisenberg model is studied. The trace of the Boltzmann weight with respect to the Hilbert space is taken in the thermodynamic limit with the number of up-spins being fixed. The expression of the trace gives an explanation why ... More

Graphical representation of the partition function for a 1-D delta-function Bose gasDec 13 2002One-dimensional repulsive delta-function bose system is studied. By only using the Bethe ansatz equation, n-particle partition functions are exactly calculated. From this expression for the n-particle partition function, the n-particle cluster integral ... More

A2ILU: Auto-accelerated ILU Preconditioner for Sparse Linear SystemsJan 23 2013Jun 19 2013The ILU-based preconditioning methods in previous work have their own parameters to improve their performances. Although the parameters may degrade the performance, their determination is left to users. Thus, these previous methods are not reliable in ... More

On one-point extensions of cluster-tilted algebrasDec 16 2011We define an operation which associates to a pair (B,M) where B is a cluster-tilted algebra and M is a B-module which lies in a local slice of B, a new cluster-tilted algebra B'. In terms of the quivers, this operation corresponds to adding one vertex ... More

Triakis Solids and Harmonic FunctionsOct 17 2012We describe the harmonic functions for certain isohedral triakis solids. They are the first examples for which polyhedral harmonics is strictly larger than group harmonics.

Melting and Mixing States of the Earth's Mantle after the Moon-Forming ImpactJun 16 2015The Earth's Moon is thought to have formed by an impact between the Earth and an impactor around 4.5 billion years ago. This impact could have been so energetic that it could have mixed and homogenized the Earth's mantle. However, this view appears to ... More

Inefficient volatile loss from the Moon-forming disk: reconciling the giant impact hypothesis and a wet MoonDec 26 2018The Earth's Moon is thought to have formed from a circumterrestrial disk generated by a giant impact between the proto-Earth and an impactor approximately 4.5 billion years ago. Since the impact was energetic, the disk would have been hot and partially ... More

Quantum teleportation with independent sources over an optical fibre networkFeb 23 2016Quantum teleportation faithfully transfers a quantum state between distant nodes in a network, enabling revolutionary information processing applications. Here we report teleporting quantum states over a 30 km optical fiber network with the input single ... More

Chip-based Quantum Key DistributionSep 02 2015Improvement in secure transmission of information is an urgent practical need for governments, corporations and individuals. Quantum key distribution (QKD) promises security based on the laws of physics and has rapidly grown from proof-of-concept to robust ... More

Investigation of the Initial State of the Moon-Forming Disk: Bridging SPH Simulations and Hydrostatic ModelsJan 14 2014According to the standard giant impact hypothesis, the Moon formed from a partially vaporized disk generated by a collision between the proto Earth and a Mars sized impactor. The initial structure of the disk significantly affects the Moon forming process, ... More

Motion of rotatory molecular motor and chemical reaction rateJun 09 2003Aug 16 2003We examine the dependence of the physical quantities of the rotatory molecular motor, such as the rotation velocity and the proton translocation rate, on the chemical reaction rate using the model based only on diffusion process. A peculiar behavior of ... More

The Yangian Deformation of the W-Algebras and and the Calogero-Sutherland modelDec 22 1994The Yangian symmetry Y(su($n$)) of the Calogero-Sutherland-Moser spin model is reconsidered. The Yangian generators are constructed from two non-commuting su($n$)-loop algebras. The latters generate an infinite dimensional symmetry algebra which is a ... More

Multicomponent Bright Solitons in F = 2 Spinor Bose-Einstein CondensatesMar 30 2007May 22 2007We study soliton solutions for the Gross--Pitaevskii equation of the spinor Bose--Einstein condensates with hyperfine spin F=2 in one-dimension. Analyses are made in two ways: by assuming single-mode amplitudes and by generalizing Hirota's direct method ... More

Revenue Prediction of Local Event using Mathematical Model of Hit PhenomenaDec 04 2011Theoretical approach to investigate human-human interaction in society performed using a many-body theory including human-human interaction. The advertisement is treated as an external force. The word of mouth (WOM) effect is included as a two-body interaction ... More

Periodic-orbit determination of dynamical correlations in stochastic processesAug 07 2007Aug 10 2007It is shown that large deviation statistical quantities of the discrete time, finite state Markov process $P_{n+1}^{(j)}=\sum_{k=1}^NH_{jk}P_n^{(k)}$, where P_n^{(j)} is the probability for the j-state at the time step n and H_{jk} is the transition probability, ... More

Defining a Metric Space of Host Logs and Operational Use CasesNov 01 2018Host logs, in particular, Windows Event Logs, are a valuable source of information often collected by security operation centers (SOCs). The semi-structured nature of host logs inhibits automated analytics, and while manual analysis is common, the sheer ... More

UAV/UGV Autonomous Cooperation: UAV Assists UGV to Climb a Cliff by Attaching a TetherMar 12 2019This paper proposes a novel cooperative system for an Unmanned Aerial Vehicle (UAV) and an Unmanned Ground Vehicle (UGV) which utilizes the UAV not only as a flying sensor but also as a tether attachment device. Two robots are connected with a tether, ... More