Rotating Bose-Einstein Condensates with a large number of VorticesWe study a harmonically-confined Bose-Einstein condensate under rotation. Vortex lattice configurations are investigated through a variational approach. Vortices with more than a unit of angular…V. Subrahmanyam·Jul 19, 2002SaveLearn
Carbon nanotube-based quantum pump in the presence of superconducting leadParametric electron pump through superconductor-carbon-nanotube based molecular devices was investigated. It is found that a dc current, which is assisted by resonant Andreev reflection, can be…Yadong Wei, Jian Wang·Jul 19, 2002SaveLearn
Parametric Statistics of Individual Energy Levels in Random HamiltoniansWe establish a general framework to explore parametric statistics of individual energy levels in disordered and chaotic quantum systems of unitary symmetry. The method is applied to the calculation…I. E. Smolyarenko, B. D. Simons·Jul 18, 2002SaveLearn
Temperature of a Compressed Bubble with Application to SonoluminescenceThe rise in temperature from the adiabatic compression of a bubble is computed in thermodynamic mean field (van der Waals) theory. It is shown that the temperature rise is higher for the noble gas…S. Sivasubramanian, A. Widom, Y. N. Srivastava·Jul 18, 2002SaveLearn
Exotic treesWe discuss the scaling properties of free branched polymers. The scaling behaviour of the model is classified by the Hausdorff dimensions for the internal geometry: dL and dH, and for the external…Z. Burda, J. Erdmann, B. Petersson et al.·Jul 18, 2002SaveLearn
The structure of small lead clustersWe have located the global minimum for all lead clusters with up to 160 atoms using a glue potential to model the interatomic interactions. The lowest-energy structures are not face-centred cubic as…Jonathan P. K. Doye, Shaun C. Hendy·Jul 17, 2002SaveLearn
Scale Invariance in disordered systems: the example of the Random Field Ising ModelWe show by numerical simulations that the correlation function of the random field Ising model (RFIM) in the critical region in three dimensions has very strong fluctuations and that in a finite…Giorgio Parisi, Nicolas Sourlas·Jul 17, 2002SaveLearn
Answer to Comment by J.B. Pendry on" Left-handed materials do not make a perfect lens"Answer to Comment by J.B. Pendry on" Left-handed materials do not make a perfect lens" by N. Garcia and M. Nieto-VesperinasN. Garcia, M. Nieto-Vesperinas·Jul 17, 2002SaveLearn
Anomalous dimensions of gauge-invariant amplitudes in massless effective gauge theories of strongly correlated systemsWe use the radial gauge to calculate the recently proposed ansatz for the physical electron propagator in such effective models of strongly correlated electron systems as the QED3 theory of the…V. P. Gusynin, D. V. Khveshchenko, M. Reenders·Jul 16, 2002SaveLearn
Universal spectral statistics of Andreev billiards: semiclassical approachThe classification of universality classes of random-matrix theory has recently been extended beyond the Wigner-Dyson ensembles. Several of the novel ensembles can be discussed naturally in the…Sven Gnutzmann, Burkhard Seif, Felix von Oppen et al.·Jul 16, 2002SaveLearn
Winning combinations of history-dependent gamesThe Parrondo effect describes the seemingly paradoxical situation in which two losing games can, when combined, become winning [Phys. Rev. Lett. 85, 24 (2000)]. Here we generalize this analysis to…Roland J. Kay, Neil F. Johnson·Jul 16, 2002SaveLearn
Effects of polydispersity on the phase coexistence diagrams in multiblock copolymers with Laser block length distributionPhase behavior of AB-multiblock copolymer melts which consists of chains with Laser distribution of A and B blocks have been investigated in the framework of the mean-field theory, where the…M. Foroutan, M. A. Jafarizadeh·Jul 16, 2002SaveLearn
Origin of the Universal Roughness Exponent of Brittle Fracture Surfaces: Correlated Percolation in the Damage ZoneWe suggest that the observed large-scale universal roughness of brittle fracture surfaces is due to the fracture process being a correlated percolation process in a self-generated quadratic damage…Alex Hansen, Jean Schmittbuhl·Jul 15, 2002SaveLearn
Level Crossing Analysis of Growing surfacesWe investigate the average frequency of positive slope να+ , crossing the height α= h- h in the surface growing processes. The exact level crossing analysis of the random deposition…F. Shahbazi, S. Sobhanian, M. Reza Rahimi Tabar et al.·Jul 13, 2002SaveLearn
Epidemic thresholds on scale-free graphs: the interplay between exponent and preferential choiceWe show for a model of scale-free graphs with biased partner choice that knowing the exponent for the degree distribution is in general not sufficient to decide epidemic threshold properties for…Ph. Blanchard, Ch. -H. Chang, T. Krueger·Jul 12, 2002SaveLearn
A slow and dark atomic beamWe demonstrate a method to produce a very slow atomic beam from a vapour cell magneto-optical trap. Atoms are extracted from the trap using the radiation pressure imbalance caused by a push beam. An…B. K. Teo, T. Cubel, G. Raithel·Jul 12, 2002SaveLearn
What is the Physical Explanation for the Very Large Ballistic Magnetoresitance Observed in Electrodeposited Nanocontacts?Recent experiments in approximately 10nm size electrodeposited Ni-Ni nanocontacts have shown ballistic magnetoresitance values of 700% stable during a week (Garcia et al Appl. Phys. Lett. 79,…N. Garcia·Jul 12, 2002SaveLearn
Bose-Einstein condensate collapse: a comparison between theory and experimentWe solve the Gross-Pitaevskii equation numerically for the collapse induced by a switch from positive to negative scattering lengths. We compare our results with experiments performed at JILA with…C. M. Savage, N. P. Robins, J. J. Hope·Jul 12, 2002SaveLearn
BEC Collapse and Dynamical Squeezing of Vacuum FluctuationsWe analyze the phenomena of Bose Novae, as described by Donley et al [Nature 412, 295 (2001)], by focusing on the behavior of excitations or fluctuations above the condensate, as driven by the…E. Calzetta, B. L. Hu·Jul 11, 2002SaveLearn
Theory of neutral and charged exciton scattering with electrons in semiconductor quantum wellsElectron scattering on both neutral (X) and charged (X-) excitons in quantum wells is studied theoretically. A microscopic model is presented, taking into account both elastic and dissociating…G. Ramon, A. Mann, E. Cohen·Jul 10, 2002SaveLearn
Thomas-Fermi approximation to static vortex states in superfluid trapped atomic gasesWe revise the Thomas-Fermi approximation for describing vortex states in Bose condensates of magnetically trapped atoms. Our approach is based on considering the hbar -> 0 limit rather than the N ->…M. Urban, P. Schuck, X. Vinas·Jul 10, 2002SaveLearn
A vertical diatomic artificial molecule in the intermediate coupling regime in a parallel and perpendicular magnetic fieldWe present experimental results for the ground state electrochemical potentials of a few electron semiconductor artificial molecule made by vertically coupling two quantum dots, in the intermediate…F. Ancilotto, D. G. Austing, M. Barranco et al.·Jul 9, 2002SaveLearn
Effects of the trapping potential on a superfluid atomic Fermi GasWe examine a dilute two-component atomic Fermi gas trapped in a harmonic potential in the superfluid phase. For experimentally realistic parameters, the trapping potential is shown to have crucial…G. M. Bruun·Jul 8, 2002SaveLearn
The activated torsion oscillation magnetometerThe activated torsion oscillation magnetometer exploits the mechanical resonance of a cantilever beam, driven by the torque exerted on the sample by an ac field applied perpendicularly to the film…G. Asti, M. Ghidini, R. Pellicelli et al.·Jul 8, 2002SaveLearn
Coherence peak in the spin susceptibility from nesting in spin-triplet superconductors; A probe for line nodes in Sr2RuO4We study the dynamical spin susceptibility χ( q,ω) for spin-triplet superconductivity. We show that a large peak at ω= 2 Δ appears in Im χzz(Q, ω), where z is the…M. Yakiyama, Y. Hasegawa·Jul 8, 2002SaveLearn