Finite temperature hydrodynamic modes of trapped quantum gasesThe hydrodynamic equations of an ideal fluid formed by a dilute quantum gas in a parabolic trapping potential are studied analytically and numerically. Due to the appearance of internal modes in the…András Csordás, Robert Graham·Dec 20, 2000SaveLearn
Mechanism of Magnetism in Stacked Nanographite: Theoretical StudyAntiferromagnetism in stacked nanographite is investigated with using the Hubbard-type model. The A-B stacking is favorable for the hexagonal nanographite with zigzag edges, in order that magnetism…Kikuo Harigaya, Naoki Kawatsu, Toshiaki Enoki·Dec 19, 2000SaveLearn
Fractional Electrons in Liquid Helium?We argue that electrons in liquid helium bubbles are not fractional, they are entangled.R. Jackiw, C. Rebbi, J. R. Schrieffer·Dec 19, 2000SaveLearn
Collective Modes of Trapped Fermi Gases in the Normal PhaseWe consider the collective mode spectrum of a normal Fermi gas in a spherical harmonic trap. Using a self-consistent random-phase-approximation, we systematically examine the effects of the two-body…G. M. Bruun·Dec 19, 2000SaveLearn
Temporally disordered Ising modelsWe present a study of the influence of different types of disorder on systems in the Ising universality class by employing both a dynamical field theory approach and extensive Monte Carlo…Juan J. Alonso, Miguel A. Munoz·Dec 19, 2000SaveLearn
Dark-Bright Solitons in Inhomogeneous Bose-Einstein CondensatesWe investigate dark-bright vector solitary wave solutions to the coupled non-linear Schrödinger equations which describe an inhomogeneous two-species Bose-Einstein condensate. While these structures…Th. Busch, J. R. Anglin·Dec 19, 2000SaveLearn
What can superconductivity learn from quantized vorticity in He-3 superfluids?In He-3 superfluids quantized vorticity can take many different forms: It can appear as distributed periodic textures, as sheets, or as lines. In the anisotropic He-3A phase in most cases the…G. E. Volovik, V. B. Eltsov, M. Krusius·Dec 19, 2000SaveLearn
Roughness of Crack Interfaces in Two-Dimensional Beam LatticesThe roughness of crack interfaces is reported in quasistatic fracture, using an elastic network of beams with random breaking thresholds. For strong disorders we obtain 0.86(3) for the roughness…Bjorn Skjetne, Torbjorn Helle, Alex Hansen·Dec 19, 2000SaveLearn
Structural, Electronic, and Magnetic Properties of MnOWe calculate the structural, electronic, and magnetic properties of MnO from first principles, using the full-potential linearized augmented planewave method, with both local-density and…J. E. Pask, D. J. Singh, I. I. Mazin et al.·Dec 18, 2000SaveLearn
Aging in glassy systems: new experiments, simple models, and open questionsWe review the most striking experimental results on aging in a variety of disordered systems, which reveal similar features but also important differences. We argue that a generic model that…Jean-Philippe Bouchaud·Dec 18, 2000SaveLearn
Phase behaviour of a hard sphere colloidal system in the presence of an external laser fieldWe study the phase behaviour of a two-dimensionally confined hard sphere colloidal system in the presence of a periodic light field of two interfering laser beams using Monte Carlo simulations. For a…Pinaki Chaudhuri, Ajay K. Sood, H. R. Krishnamurthy·Dec 18, 2000SaveLearn
Quantum Algorithms for Fermionic SimulationsWe investigate the simulation of fermionic systems on a quantum computer. We show in detail how quantum computers avoid the dynamical sign problem present in classical simulations of these systems,…G. Ortiz, J. E. Gubernatis, E. Knill et al.·Dec 18, 2000SaveLearn
Polytetrahedral ClustersBy studying the structures of clusters bound by a model potential that favours polytetrahedral order, we find a previously unknown series of `magic numbers' (i.e. sizes of special stability)…Jonathan Doye, David Wales·Dec 18, 2000SaveLearn
Spectral Decompositions for Evolution Opertors of Mixing Dynamical SystemsSpectral decompositions for the evolution operator on an energy shell in phase space are constructed for the free motion on compact 2D surfaces of constant negative curvature. Applications to quantum…Stephen Roberts, Boris Muzykantskii·Dec 18, 2000SaveLearn
On a universal mechanism for long ranged volatility correlationsWe propose a general interpretation for long-range correlation effects in the activity and volatility of financial markets. This interpretation is based on the fact that the choice between…Jean-Philippe Bouchaud, Irene Giardina, Marc Mezard·Dec 18, 2000SaveLearn
Phonons and Forces: Momentum versus Pseudomomentum in Moving FluidsI provide a pedagogical introduction to the notion of pseudomomentum for waves in a medium, and show how changes in pseudomomentum may sometimes be used to compute real forces. I then explain how…Michael Stone·Dec 17, 2000SaveLearn
Time evolution of tetragonal-orthorhombic ferroelasticsWe study numerically the time evolution of two-dimensional (2D) domain patterns in proper tetragonal-orthorhombic (T-O) ferroelastics. Our results, found by solving equations of motion derived from…S. H. Curnoe, A. E. Jacobs·Dec 17, 2000SaveLearn
Indivisibility of electron bubbles in heliumA recent proposal by Maris[1], that single electron bubbles in helium might fission into separate, particle-like entities, does not properly take into account the failure of the adiabatic…Veit Elser·Dec 17, 2000SaveLearn
The Volatility in a Multi-share Financial Market ModelSingle index financial market models cannot account for the empirically observed complex interactions between shares in a market. We describe a multi-share financial market model and compare…Adam Ponzi·Dec 16, 2000SaveLearn
Off-axis vortices in trapped Bose condensed gases: angular momentum and frequency splittingWe consider non centered vortices and their arrays in a cylindrically trapped Bose-Einstein condensate at zero temperature. We study the kinetic energy and the angular momentum per particle in the…Montserrat Guilleumas, Robert Graham·Dec 15, 2000SaveLearn
Elementary excitation families and their frequency ordering in cylindrically symmetric Bose-Einstein condensatesWe present a systematic classification of the elementary excitations of Bose-Einstein condensates in cylindrical traps in terms of their shapes. The classification generalizes the concept of families…A. A. Penckwitt, R. J. Ballagh·Dec 15, 2000SaveLearn
Nonequilibrium dynamics of random field Ising spin chains: exact results via real space RGNon-equilibrium dynamics of classical random Ising spin chains are studied using asymptotically exact real space renormalization group. Specifically the random field Ising model with and without an…Daniel S. Fisher, Pierre Le Doussal, Cecile Monthus·Dec 15, 2000SaveLearn
Stochastic strategies in the Minority GameWe show analytically how the fluctuations (i.e. standard deviation) in the Minority Game (MG) can decrease below the random coin-toss limit if the agents use more general, stochastic strategies. This…M. Hart, P. Jefferies, N. F. Johnson et al.·Dec 15, 2000SaveLearn
Renormalization-group study of gate charge effects in Josephson-junction chainsWe study the quantum phase transition in a chain of superconducting grains, coupled by Josephson junctions, with emphasis on the effects of gate charges induced on the grains. At zero temperature the…M. Y. Choi, Sung Wu Rhee, Minchul Lee et al.·Dec 14, 2000SaveLearn
The phase diagram of the lattice Calogero-Sutherland modelWe introduce a lattice version of the Calogero Sutherland model adapted to describe 1/d2 pairwise interacting steps with discrete positions on a vicinal surface. The configurational free…E. Le Goff, L. Barbier, B. Salanon·Dec 14, 2000SaveLearn