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Condensed Matter papers — page 121

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Coulomb gap in a model with finite charge transfer energy
The Coulomb gap in a donor-acceptor model with finite charge transfer energy Δ describing the electronic system on the dielectric side of the metal-insulator transition is investigated by means of…
S. A. Basylko, P. J. Kundrotas, V. A. Onischouk et al.Mar 17, 2000
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Segregation in a competing and evolving population
We study a recently proposed model in which an odd number of agents are competing to be in the minority. The agents have one strategy in hand which is to follow the most recent history. Each agent is…
P. M. Hui, T. S. Lo, N. F. JohnsonMar 17, 2000
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Hydrogen Bonds in Polymer Folding
The thermodynamics of a homopolymeric chain with both Van der Waals and highly-directional hydrogen bond interaction is studied. The effect of hydrogen bonds is to reduce dramatically the entropy of…
J. Borg, M. H. Jensen, K. Sneppen et al.Mar 17, 2000
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Theory for two-photon photoemission: transport and temperature effects
Using a theory which treats on equal footing transport of excited electrons and electron-phonon scattering, we are able to explain the temperature dependence of the relaxation time in Cu as recently…
R. Knorren, G. Bouzerar, K. H. BennemannMar 17, 2000
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Glass transition of a particle in a random potential, front selection in nonlinear RG and entropic phenomena in Liouville and SinhGordon models
We study via RG, numerics, exact bounds and qualitative arguments the equilibrium Gibbs measure of a particle in a d-dimensional gaussian random potential with translationally invariant…
David Carpentier, Pierre Le DoussalMar 16, 2000
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Effects of spin-elastic interactions in frustrated Heisenberg antiferromagnets
The Heisenberg antiferromagnet on a compressible triangular lattice in the spin- wave approximation is considered. It is shown that the interaction between quantum fluctuations and elastic degrees of…
Yu. Gaididei, H. BüttnerMar 16, 2000
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Description of Dynamic Properties of Finite Electron Systems in Density Functional Theory
The self consistent version of the density functional theory (DFT) is presented, which allows to calculate the ground state and dynamic properties of finite multi-electron systems such as atoms,…
M. Ya. Amusia, V. R. ShaginyanMar 16, 2000
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Structural properties and quasiparticule energies of cubic SrO, MgO and SrTiO3
The structural properties and the band structures of the charge-transfer insulating oxides SrO, MgO and SrTiO3 are computed both within density functional theory in the local density approximation…
G. Cappellini, S. Bouette-Russo, B. Amadon et al.Mar 16, 2000
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Creation of Skyrmions in a Spinor Bose-Einstein Condensate
We propose a scheme for the creation of skyrmions (coreless vortices) in a Bose-Einstein condensate with hyperfine spin F=1. In this scheme, four traveling-wave laser beams, with Gaussian or…
Karl-Peter Marzlin, Weiping Zhang, Barry C. SandersMar 16, 2000
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First excited state calculation using different phonon bases for the two-site Holstein model
The single-electron energy and static charge-lattice deformation correlations have been calculated for the first excited state of a two-site Holstein model within perturbative expansions using…
Jayita Chatterjee, A. N. DasMar 15, 2000
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Two-magnon Raman scattering in insulating cuprates: Modifications of the effective Raman operator
Calculations of Raman scattering intensities in spin 1/2 square-lattice Heisenberg model, using the Fleury-Loudon-Elliott theory, have so far been unable to describe the broad line shape and…
P. J. Freitas, R. R. P. SinghMar 14, 2000
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On the Thomas-Fermi approximation in the bulk of trapped Bose-Einstein condensed gases
Corrections to the Thomas-Fermi-type solution of the Gross-Pitaevskii equation are inevitable in order to get correctly the frequencies of the low lying modes out of the Bogolyubov equations. These…
Gyula Bene, Peter SzepfalusyMar 14, 2000
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Zero temperature correlations in trapped Bose-Einstein condensates
We introduce a family of correlated trial wave functions for the N-particle ground state of an interacting Bose gas in a harmonic trap. For large N, the correlations lead to a relative energy…
Walter T. StrunzMar 14, 2000
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Electronic structure of polychiral carbon nanotubes
Most of the works devoted so far to the electronic band structure of multiwall nanotubes have been restricted to the case where the individual layers have the same helicity. By comparison, much less…
Ph. Lambin, V. Meunier, A. RubioMar 14, 2000
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The system with exponentially degenerate vacuum state
I suggest and examine artificial material which has exponentially degenerate vacuum state. The corresponding Hamiltonian contains only exotic four-spin interaction term. Each vacuum state is realized…
G. K. SavvidyMar 13, 2000
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One-Dimensional Textures and Critical Velocity in Superfluid 3He-A
We study theoretically the stability of flow in superfluid 3He-A. The calculations are done using a one-dimensional model where the order parameter depends only on the coordinate in the direction of…
J. Kopu, R. Hänninen, E. V. ThunebergMar 13, 2000
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Compressibility crossover and quantum opening of a gap for two dimensional disordered clusters with Coulomb repulsion
Using Hartree-Fock orbitals with residual Coulomb repulsion, we study spinless fermions in a two dimensional random potential. When we increase the system size L at fixed particle density, the size…
Giuliano Benenti, Xavier Waintal, Jean-Louis Pichard et al.Mar 13, 2000
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Peculiarities of Raman Spectra Shape in the Disordered Ferroelectrics
Theory of the first order Raman scattering (FOR) line shape allowing for nonlinear and correlation effects contribution to inhomogeneous broadening as well as dynamic mechanisms of homogeneous…
M. D. Glinchuk, I. V. KondakovaMar 12, 2000
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Two Stages in the evolution of binary alkali Bose-Einstein condensate mixtures towards phase segregation
Two stages of quantum spinodal decomposition is proposed and analyzed for this highly non-equilibrium process. Both time and spatial scales for the process are found. Qualitative agreement with…
P. Ao, S. T. ChuiMar 10, 2000
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Breakdown of the standard Perturbation Theory and Moving Boundary Approximation for "Pulled" Fronts
The derivation of a Moving Boundary Approximation or of the response of a coherent structure like a front, vortex or pulse to external forces and noise, is generally valid under two conditions: the…
Ute Ebert, Wim van SaarloosMar 10, 2000
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Front propagation into unstable states: Universal algebraic convergence towards uniformly translating pulled fronts
Fronts that start from a local perturbation and propagate into a linearly unstable state come in two classes: pulled and pushed. ``Pulled'' fronts are ``pulled along'' by the…
Ute Ebert, Wim van SaarloosMar 10, 2000
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Self organization in a minority game: the role of memory and a probabilistic approach
A minority game whose strategies are given by probabilities p, is replaced by a 'simplified' version that makes no use of memories at all. Numerical results show that the corresponding…
E. Burgos, Horacio CevaMar 10, 2000
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Comment on "Quantum diffusion of 3-He impurities in solid 4- He"
In this comment I show that the experimental data on quantum diffusion of 3-He impurities in solid 4-He can be explained using the adopted quasiparticle theory. The contention by E.G. Kisvarsanyi and…
Dimitar I. PushkarovMar 10, 2000
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Membrane boundary condition
Using a microscopic phase-space model of the membrane system, the boundary condition at a membrane is derived. According to the condition, the substance flow across the membrane is proportional to…
Tadeusz Kosztolowicz, Stanislaw MrowczynskiMar 10, 2000
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Classical mechanics technique for quantum linear response
It is shown that the lowest excitation energies of a quantum many-fermion system in the random phase approximation (RPA) can be obtained by minimizing an effective classical energy functional. The…
E. V. TsiperMar 10, 2000
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