Critical Discussion of the 2-Loop Calculations for the KPZ-EquationIn this article, we perform a careful analysis of the renormalization procedure used in existing calculations to derive critical exponents for the KPZ-equation at 2-loop order. This analysis explains…Kay Joerg Wiese·Jun 2, 1997SaveLearn
Hydrodynamic excitations of Bose condensates in anisotropic trapsThe collective excitations of Bose condensates in anisotropic axially symmetric harmonic traps are investigated in the hydrodynamic and Thomas-Fermi limit. We identify an additional conserved…Martin Fliesser, András Csordás, Péter Szépfalusy et al.·Jun 1, 1997SaveLearn
Exchange coupling between magnetic layers across non-magnetic superlatticesThe oscillation periods of the interlayer exchange coupling are investigated when two magnetic layers are separated by a metallic superlattice of two distinct non-magnetic materials. In spite of the…M. S. Ferreira·May 30, 1997SaveLearn
Phase separation in the neutral Falicov-Kimball modelThe Falicov-Kimball model consists of spinless electrons and classical particles (ions) on a lattice. The electrons hop between nearest neighbor sites while the ions do not. We consider the model…Tom Kennedy·May 30, 1997SaveLearn
Collective Modes in Supersolid 4HeWe derive the hydrodynamic equations of motion of solid and supersolid 4He, that describe the collective modes of these phases. In particular, the usual hydrodynamics is modified in such a way that…M. J. Bijlsma, H. T. C. Stoof·May 30, 1997SaveLearn
Transfer Matrix DMRG for Thermodynamics of One-Dimensional Quantum SystemsThe transfer matrix DMRG method for one dimensional quantum lattice systems has been developed by considering the symmetry property of the transfer matrix and introducing the asymmetric reduced…Xiaoqun Wang, Tao Xiang·May 29, 1997SaveLearn
Spin-Reversal Transition in Ising Model under Pulsed FieldIn this communication we report the existence of a dynamic ``spin-reversal'' transition in an Ising system perturbed by a pulsed external magnetic field. The transition is achieved by tuning…A. Misra, B. K. Chakrabarti·May 29, 1997SaveLearn
C-axis Josephson Tunneling Between YBCO and Pb: Direct Evidence for Mixed Order Parameter Symmetry in a High-Tc SuperconductorWe report a new class of c-axis Josephson tunneling experiments in which a conventional superconductor (Pb) is deposited across a single twin boundary of a YBa2Cu3O7-δ crystal. We measure the…K. A. Kouznetsov, A. G. Sun, B. Chen et al.·May 28, 1997SaveLearn
Vortex Pinning and Non-Hermitian Quantum MechanicsA delocalization phenomenon is studied in a class of non-Hermitian random quantum-mechanical problems. Delocalization arises in response to a sufficiently large constant imaginary vector potential.…Naomichi Hatano, David R. Nelson·May 27, 1997SaveLearn
Two-component radiation model of the sonoluminescing bubbleBased on the experimental data from Weninger, Putterman & Barber, Phys. Rev. (E), 54, R2205 (1996), we offer an alternative interpretation of their experimetal results. A model of sonoluminescing…David Tsiklauri·May 27, 1997SaveLearn
Polymer stars in three dimensions. Three loop resultsWe study scaling properties of self avoiding polymer stars and networks of arbitrary given but fixed topology. We use massive field theoretical renormalization group framework to calculate critical…Christian von Ferber, Yurij Holovatch·May 27, 1997SaveLearn
Field theoretic operators for multifractal momentsWhile multifractal spectra are convex, general field theoretic arguments show that power of field operators ϕf yield a concave spectrum of exponents as function of f. This is resolved by…Christian von Ferber, Yurij Holovatch·May 27, 1997SaveLearn
Copolymer Networks: Multifractal dimension spectra in polymer field theoryWe explore the rich scaling behavior of copolymer networks in solution. We establish a field theoretic description in terms of composite operators. Our 3rd order resummation of the spectrum of…Christian von Ferber, Yurij Holovatch·May 27, 1997SaveLearn
Quantum Phase Transitions for Bosons in One DimensionWe study the ground state phase diagram and the critical properties of interacting Bosons in one dimension by means of a quantum Monte Carlo technique. The direct experimental realization is a chain…Reinhard Baltin, Karl-Heinz Wagenblast·May 26, 1997SaveLearn
On-line learning in a discrete state spaceOn-line learning of a rule given by an N-dimensional Ising perceptron, is considered for the case when the student is constrained to take values in a discrete state space of size LN. For L=2 no…W. Kinzel, R. Urbanczik·May 26, 1997SaveLearn
Density-functional theory calculations for poly-atomic systems: Electronic structure, static and elastic properties and ab initio molecular dynamicsThe package "fhi96md" is an efficient code to perform density-functional theory total-energy calculations for materials ranging from insulators to transition metals. The package employs…Michel Bockstedte, Alexander Kley, Joerg Neugebauer et al.·May 26, 1997SaveLearn
Non-monotonic field-dependence of the ZFC magnetization peak in some systems of magnetic nanoparticlesWe have performed magnetic measurements on a diluted system of gamma-Fe2O3 nanoparticles (~7nm), and on a ferritin sample. In both cases, the ZFC-peak presents a non-monotonic field dependence, as…R. Sappey, E. Vincent, N. Hadacek et al.·May 23, 1997SaveLearn
Collective and single particle excitations of a trapped Bose gasThe density of states of a Bose-condensed gas confined in a harmonic trap is investigated. The predictions of Bogoliubov theory are compared with the ones of Hartree-Fock theory and of the…F. Dalfovo, S. Giorgini, M. Guilleumas et al.·May 23, 1997SaveLearn
Sonoluminescence: Coupling to an Applied Magnetic FieldWe investigate several means of coupling between a sonoluminescing bubble and an applied magnetic field. Recent experiments show a strong quadratic dependence between the forcing pressures required…B. A. DiDonna, T. A. Witten, J. B. Young·May 23, 1997SaveLearn
Asymptotics of the trap-dominated Gunn effect in p-type GeWe present an asymptotic analysis of the Gunn effect in a drift-diffusion model---including electric-field-dependent generation-recombination processes---for long samples of strongly compensated…L. L. Bonilla, P. J. Hernando, M. A. Herrero et al.·May 23, 1997SaveLearn
Onsager Loop-Transition and First Order Flux-Line Lattice Melting in High-Tc SuperconductorsMonte-Carlo simulations in conjunction with finite-size scaling analysis are used to investigate the (H,T)-phase diagram in uniaxial anisotropic high- Tc superconductors, both in zero magnetic…A. K. Nguyen, A. Sudbø·May 22, 1997SaveLearn
Exact Momentum Distribution of a Fermi Gas in One DimensionWe introduce an exactly solvable model of a fermi gas in one dimension and compute the momentum distribution exactly. This is based on a generalisation of the ideas of bosonization in one dimension.…Girish S. Setlur·May 22, 1997SaveLearn
Spectral diffusion on ultralong time scales in low temperature glassesA dynamical theory is constructed to describe spectral diffusion in glasses in the temperature range near 1 Kelvin on long time scales. The theory invokes interacting tunneling centers (TLS) which…Peter Neu, David R. Reichman, Robert J. Silbey·May 22, 1997SaveLearn
Monte Carlo Simulation of the Short-time Behaviour of the Dynamic XY ModelDynamic relaxation of the XY model quenched from a high temperature state to the critical temperature or below is investigated with Monte Carlo methods. When a non-zero initial magnetization is…K. Okano, L. Schuelke, K. Yamagishi et al.·May 22, 1997SaveLearn
The short-time behaviour of a kinetic Ashkin-Teller model on the critical lineWe simulate the kinetic Ashkin-Teller model with both ordered and disordered initial states, evolving in contact with a heat-bath at the critical temperature. The power law scaling behaviour for the…Z. B. Li, X. W. Liu, L. Schuelke et al.·May 22, 1997SaveLearn