A new class of integrable diffusion-reaction processesWe consider a process in which there are two types of particles, A and B, on an infinite one-dimensional lattice. The particles hop to their adjacent sites, like the totally asymmetric exclusion…M. Alimohammadi, N. Ahmadi·Feb 17, 2000SaveLearn
Comparison of two methods for calculating nucleation ratesFirst-order phase transitions that proceed via nucleation of bubbles are described by the homogeneous nucleation theory of Langer. The nucleation rate is one of the most interesting parameters of…G. Munster, A. Strumia, N. Tetradis·Feb 17, 2000SaveLearn
Ion-Beam Induced Current in High-Resistance MaterialsThe peculiarities of electric current in high-resistance materials, such as semiconductors or semimetals, irradiated by ion beams are considered. It is shown that after ion--beam irradiation an…V. I. Yukalov, E. P. Yukalova·Feb 17, 2000SaveLearn
Ferromagnetism and Canted Spin Phase in AlAs/GaMnAs Single Quantum Wells: Monte Carlo SimulationThe magnetic order resulting from a confinement-adapted Ruderman-Kittel-Kasuya-Yosida indirect exchange between magnetic moments in the metallic phase of a AlAs/Ga(1-x)Mn(x)As quantum well is studied…M. A. Boselli, A. Ghazali, I. C. da Cunha Lima·Feb 16, 2000SaveLearn
Vibrational properties of the one-component σ phaseA structural model of a one-component σ-phase crystal has been constructed by means of molecular dynamics simulation. The phonon dispersion curves and the vibrational density of states were…S. I. Simdyankin, S. N. Taraskin, M. Dzugutov et al.·Feb 16, 2000SaveLearn
Asymptotic form of two-point correlation function of the XXZ spin chainCorrelation 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…Yasuhiro Fujii, Miki Wadati·Feb 15, 2000SaveLearn
Effect of the Orbital Level Difference in Doped Spin-1 ChainsDoping of a two-orbital chain with mobile S=1/2 Fermions and strong Hund's rule couplings stabilizing the S=1 spins strongly depends on the presence of a level difference among these orbitals. By…Beat Ammon, Masatoshi Imada·Feb 14, 2000SaveLearn
Heat conduction in one dimensional nonintegrable systemsTwo classes of 1D nonintegrable systems represented by the Fermi-Pasta-Ulam (FPU) model and the discrete ϕ4 model are studied to seek a generic mechanism of energy transport in microscopic level…Bambi Hu, Baowen Li, Hong Zhao·Feb 14, 2000SaveLearn
Quantum Tunneling of Magnetization in Molecular Complexes with Large Spins. Effect of the EnvironmentWe review the present state of theory and experiments on the quantum tunneling of magnetization in mesoscopic spin systems. Most attention is paid to the relaxation of magnetization in the molecular…Igor Tupitsyn, Bernard Barbara·Feb 12, 2000SaveLearn
Wannier Functions for Lattices in a Magnetic Field II: Extensions to Irrational FieldsThis paper extends earlier work on the definition of Wannier functions for Bloch electrons in a magnetic field. Extensions to irrational as well as rational magnetic fields are defined, and their…Michael Wilkinson·Feb 12, 2000SaveLearn
Excitons and Polarons in Quantum WellsWe study properties of polarons and excitons confined to a potential generated in a planar semiconductor heterostructure of the Ga1-xAlxAs/GaAs/Ga1-xAlxAs type. In contrast with results…B. Gerlach, M. A. Smondyrev·Feb 11, 2000SaveLearn
Sum Rule Approach to Collective Oscillations of Boson-Fermion Mixed Condensate of Alkali AtomsThe behavior of collective oscillations of a trapped boson-fermion mixed condensate is studied in the sum rule approach. Mixing angle of bosonic and fermionic multipole operators is introduced so…T. Miyakawa, T. Suzuki, H. Yabu·Feb 10, 2000SaveLearn
Structure and Magnetism of well-defined cobalt nanoparticles embedded in a niobium matrixOur recent studies on Co-clusters embedded in various matrices reveal that the co-deposition technique (simultaneous deposition of two beams : one for the pre-formed clusters and one for the matrix…M. Jamet, V. Dupuis, P. Melinon et al.·Feb 9, 2000SaveLearn
On the evaluation of the specific heat and general off-diagonal n-point correlation functions within the loop algorithmWe present an efficient way to compute diagonal and off-diagonal n-point correlation functions for quantum spin-systems within the loop algorithm. We show that the general rules for the evaluation of…J. V. Alvarez, Claudius Gros·Feb 9, 2000SaveLearn
Thermodynamics of the Spin-1/2 Antiferromagnetic Uniform Heisenberg ChainWe present a new application of the traditional thermodynamic Bethe ansatz to the spin-1/2 antiferromagnetic uniform Heisenberg chain and derive exact nonlinear integral equations for just two…A. Klümper, D. C. Johnston·Feb 9, 2000SaveLearn
Modelling an Imperfect MarketWe propose a simple market model where agents trade different types of products with each other by using money, relying only on local information. Value fluctuations of single products, combined with…Raul Donangelo, Alex Hansen, Kim Sneppen et al.·Feb 9, 2000SaveLearn
Thermodynamic properties of the periodic nonuniform spin-1/2 isotropic XY chains in a transverse fieldUsing the Jordan-Wigner transformation and the continued-fraction method we calculate exactly the density of states and thermodynamic quantities of the periodic nonuniform spin-1/2 isotropic XY chain…Oleg Derzhko, Johannes Richter, Oles' Zaburannyi·Feb 9, 2000SaveLearn
Ab initio treatment of electron correlations in polymers: lithium hydride chain and beryllium hydride polymerCorrelated ab initio electronic structure calculations are reported for the polymers lithium hydride chain [LiH]∞ and beryllium hydride [Be2H4]∞. First, employing a…Ayjamal Abdurahman, Alok Shukla, Michael Dolg·Feb 9, 2000SaveLearn
Incorporation of Density Matrix Wavefunctions in Monte Carlo Simulations: Application to the Frustrated Heisenberg ModelWe combine the Density Matrix Technique (DMRG) with Green Function Monte Carlo (GFMC) simulations. The DMRG is most successful in 1-dimensional systems and can only be extended to 2-dimensional…M. S. L. du Croo de Jongh, J. M. J. van Leeuwen, W. van Saarloos·Feb 8, 2000SaveLearn
Delocalization in the Anderson model due to a local measurementWe study a one-dimensional Anderson model in which one site interacts with a detector monitoring the occupation of that site. We demonstrate that such an interaction, no matter how weak, leads to…S. A. Gurvitz·Feb 8, 2000SaveLearn
Extensive Chaos in the Nikolaevskii ModelWe carry out a systematic study of a novel type of chaos at onset ("soft-mode turbulence") based on numerical integration of the simplest one dimensional model. The chaos is characterized by…Hao-wen Xi, Raul Toral, J. D. Gunton et al.·Feb 8, 2000SaveLearn
Influence of center-of-mass correlations on spontaneous emission and Lamb shift in dense atomic gasesLocal field effects on the rate of spontaneous emission and Lamb shift in a dense gas of atoms are discussed taking into account correlations of atomic center-of-mass coordinates. For this the exact…M. Fleischhauer·Feb 7, 2000SaveLearn
Finite-time singularity in the dynamics of the world population, economic and financial indicesContrary to common belief, both the Earth's human population and its economic output have grown faster than exponential, i.e., in a super-Malthusian mode, for most of the known history. These…Anders Johansen, Didier Sornette·Feb 5, 2000SaveLearn
Fermi systems with long scattering lengthsGround state energies and superfluid gaps are calculated for degenerate Fermi systems interacting via long attractive scattering lengths such as cold atomic gases, neutron and nuclear matter. In the…H. Heiselberg·Feb 3, 2000SaveLearn
Second Topological Moment < m2 > of Two Closed Entangled PolymersWe calculate the second topological moment < m2 > of entanglement of two closed polymers P1 and P2 in a solution. The result holds approximately for a closed polymer linked to many others,…F. Ferrari, H. Kleinert, I. Lazzizzera·Feb 3, 2000SaveLearn