Casimir effect around a screw dislocationIn this work, it is shown that a non-zero vacuum energy density (the Casimir energy) for a scalar field appears in a continuous elastic solid due to the presence of a topological defect, the screw…Ivan Pontual, Fernando Moraes·Jul 16, 1996SaveLearn
Localized Flux Lines and the Bose GlassColumnar defects provide effective pinning centers for magnetic flux lines in high--T c superconductors. Utilizing a mapping of the statistical mechanics of directed lines to the quantum…Uwe C. Täuber·Jul 16, 1996SaveLearn
Phase Transitions in Quantum DotsWe perform Hartree-Fock calculations to show that quantum dots (i.e. two dimensional systems of up to twenty interacting electrons in an external parabolic potential) undergo a gradual transition to…H. -M. Muller, S. E. Koonin·Jul 15, 1996SaveLearn
Magnetic correlations in deuteronium jarosite, a model S=5/2 Kagome antiferromagnetDeuteronium jarosite, (D3O)Fe3(SO4)2(OD)6, contains a kagome lattice of Heisenberg spins, S=5/2, with a coverage of 97+-1%. DC and AC susceptibility measurements show strong in-plane…A. S. Wills, A Harrison, S. A. M. Mentink et al.·Jul 15, 1996SaveLearn
Low energy excitations of the t-J model in 1D and 2DWe present an exact diagonalization study of the low energy singlet and triplet states for both 1D and 2D t-J model. A scan of the parameter ratio J/t shows that for nearly all low energy states in…R. Eder, Y. C. Chen, H. Q. Lin et al.·Jul 15, 1996SaveLearn
Significance of the non-2-spinon part of S(q,ω) in the one-dimensional S=1/2 Heisenberg antiferromagnet at zero temperatureThe impact of the non-2-spinon excitations of the one-dimensional S=1/2 Heisenberg antiferromagnet on the integrated intensity, the susceptibility, the frequency moments, and the Euclidian time…A Fledderjohann, K H Mütter, M Karbach et al.·Jul 15, 1996SaveLearn
Phase-dependent magnetoconductance fluctuations in a chaotic Josephson junctionMotivated by recent experiments by Den Hartog et al., we present a random-matrix theory for the magnetoconductance fluctuations of a chaotic quantum dot which is coupled by point contacts to two…P. W. Brouwer, C. W. J. Beenakker·Jul 15, 1996SaveLearn
Full capacitance matrix of coupled quantum dot arrays: static and dynamical effectsWe numerically calculated the full capacitance matrices for both one-dimensional (1D) and two-dimensional (2D) quantum-dot arrays. We found it is necessary to use the full capacitance matrix in…C. B. Whan, J. White, T. P. Orlando·Jul 15, 1996SaveLearn
Transport properties of a quantum dot with superconducting leadsWe report a numerical study of transport properties of a quantum dot with superconducting leads. We introduce a general phenomenological model of quantum dot transport, in which electron tunnel rates…C. B. Whan, T. P. Orlando·Jul 15, 1996SaveLearn
Fluctuation Induced Drift and Current Reversal in Symmetric PotentialsWe explore the motion of a classical particle in a symmetric potential with non-Gaussian skewed white noise. We show analytically and numerically that the presence of nonzero odd moments leads to a…Rangan Lahiri·Jul 14, 1996SaveLearn
Coherent `ab' and `c' transport theory of high-Tc cupratesWe propose a microscopic theory of the `c'-axis and in-plane transport of copper oxides based on the bipolaron theory and the Boltzmann kinetics. The fundamental relationship between the…A. S. Alexandrov, V. V. Kabanov, N. F. Mott·Jul 14, 1996SaveLearn
Stress Propagation and Arching in Static SandpilesWe present a new approach to the modelling of stress propagation in static granular media, focussing on the conical sandpile constructed from a point source. We view the medium as consisting of…J. P. Wittmer, M. E. Cates, P. Claudin·Jul 13, 1996SaveLearn
Griffiths singularities in the two dimensional diluted Ising modelWe study numerically the probability distribution of the Yang-Lee zeroes inside the Griffiths phase for the two dimensional site diluted Ising model and we check that the shape of this distribution…Juan J. Ruiz-Lorenzo·Jul 13, 1996SaveLearn
Inter-layer Edge Tunneling and Transport Properties in Double-Layer Quantum Hall SystemsA theory of transport in the quantum Hall regime is developed for separately contacted double-layer electron systems. Inter-layer tunneling provides a channel for equilibration of the distribution…D. Yoshioka, A. H. MacDonald·Jul 13, 1996SaveLearn
Local Electronic Structure of a Single Magnetic Impurity in a SuperconductorThe electronic structure near a single classical magnetic impurity in a superconductor is determined using a fully self-consistent Koster-Slater algorithm. Localized excited states are found within…Michael E. Flatte', Jeff M. Byers·Jul 12, 1996SaveLearn
Averaged Methods for Vortex-String EvolutionWe discuss friction-dominated vortex-string evolution using a new analytic model recently developed by the authors. By treating the average string velocity, as well as the characteristic lengthscale,…C. J. A. P. Martins, E. P. S. Shellard·Jul 12, 1996SaveLearn
Phase transitions and critical behaviour in one-dimensional non-equilibrium kinetic Ising models with branching annihilating random walk of kinksOne-dimensional non-equilibrium kinetic Ising models evolving under the competing effect of spin flips at zero temperature and nearest-neighbour spin exchanges exhibiting directed percolation-like…N. Menyhard, G. Odor·Jul 12, 1996SaveLearn
Entropic Sampling and Natural Selection in Biological EvolutionWith a view to connecting random mutation on the molecular level to punctuated equilibrium behavior on the phenotype level, we propose a new model for biological evolution, which incorporates random…M. Y. Choi, H. Y. Lee, D. Kim et al.·Jul 12, 1996SaveLearn
Mixed-state penetration depths in s-wave and d-wave superconductorsWe report on a microscopic calculation of the current and magnetic field distribution in the mixed state of model s-wave and d-wave superconductors. For the d-wave case, we find that corrections to…Yong Wang, A. H. MacDonald·Jul 12, 1996SaveLearn
Multifractal Dimensions for Branched GrowthA recently proposed theory for diffusion-limited aggregation (DLA), which models this system as a random branched growth process, is reviewed. Like DLA, this process is stochastic, and ensemble…Thomas C. Halsey, Katsuya Honda, Bertrand Duplantier·Jul 12, 1996SaveLearn
Transport properties in resonant tunneling heterostructuresWe use an adiabatic approximation in terms of instantaneous resonances to study the steady-state and time-dependent transport properties of interacting electrons in biased resonant tunneling…Carlo Presilla, Johannes Sjöstrand·Jul 12, 1996SaveLearn
Avalanche size distribution in a random walk modelWe introduce a simple model for the size distribution of avalanches based on the idea that the front of an avalanche can be described by a directed random walk. The model captures some of the…T. Jonsson, J. F. Wheater·Jul 12, 1996SaveLearn
Optimal barrier subdivision for Kramers' escape rateWe examine the effect of subdividing the potential barrier along the reaction coordinate on Kramers' escape rate for a model potential. Using the known supersymmetric potential approach, we show…Mulugeta Bekele, G. Ananthakrishna, N. Kumar·Jul 12, 1996SaveLearn
The random link approximation for the Euclidean traveling salesman problemThe traveling salesman problem (TSP) consists of finding the length of the shortest closed tour visiting N ``cities''. We consider the Euclidean TSP where the cities are distributed randomly…N. J. Cerf, J. Boutet de Monvel, O. Bohigas et al.·Jul 11, 1996SaveLearn
Exact results for resonating valence bonds states on 2D (narrow) systemsIt is shown that the problem of calculating spin-spin correlation functions, in the dimers RVB states, on a possibly diluted 2D square lattice, can be formulated in terms of a transfer matrix. The…Moshe Havilio·Jul 11, 1996SaveLearn