Time-dependent optical linewidth in fluctuating environments: Stochastic modelsTime-resolved optical lineshapes are calculated using a second-order inhomogeneous cumulant expansion. The calculation shows that in the inhomogeneous limit the optical spectra are determined solely…Gregor Diezemann·Aug 31, 2001SaveLearn
Stochastic models for heterogeneous relaxation: Application to inhomogeneous optical lineshapesDynamic heterogeneity has often been modeled by assuming that a single-particle observable, fluctuating at a molecular scale, is influenced by its coupling to environmental variables fluctuating on a…Gregor Diezemann, Gerald Hinze, Hans Sillescu·Aug 31, 2001SaveLearn
Phase states in amorphous carbonAmorphous carbon (a-C) formed under energetic atom deposition and by cooling of a melt by MD simulations in a wide P,T-range is investigated. Simulations of a-C formation with atomic beam…A. Bakai, Yu. Turkin, M. Fateev·Aug 30, 2001SaveLearn
Dynamic Critical Phenomena in Trapped Bose GasesNonlinear dynamics of a trapped Bose-Einstein condensate, subject to the action of a resonant external field, is studied. This field produces a spatio-temporal modulation of the trapping potential…V. I. Yukalov, E. P. Yukalova, V. S. Bagnato·Aug 30, 2001SaveLearn
Theory of coherent Bragg spectroscopy of a trapped Bose-Einstein condensateWe present a detailed theoretical analysis of Bragg spectroscopy from a Bose-Einstein condensate at T=0K. We demonstrate that within the linear response regime, both a quantum field theory treatment…P. B. Blakie, R. J. Ballagh, C. W. Gardiner·Aug 29, 2001SaveLearn
The liquid-glass transition of silicaWe studied the liquid-glass transition of SiO2 by means of replica theory, utilizing an effective pair potential which was proved to reproduce a few experimental features of silica. We found a…B. Coluzzi, P. Verrocchio·Aug 28, 2001SaveLearn
Anisotropic scaling and generalized conformal invariance at Lifshitz pointsA new variant of the Wolff cluster algorithm is proposed for simulating systems with competing interactions. This method is used in a high-precision study of the Lifshitz point of the 3D ANNNI model.…Malte Henkel, Michel Pleimling·Aug 28, 2001SaveLearn
Universal solutions for interacting bosons in one-dimensional harmonic trapsWe consider systems of interacting bosons confined to one-dimensional harmonic traps. In the limit of perturbatively weak two-body interactions the system exhibits several universal states that are…Thomas Papenbrock·Aug 28, 2001SaveLearn
Theory of the cold collision frequency shift in 1S--2S spectroscopy of Bose-Einstein-condensed and non-condensed hydrogenWe show that a correct formulation of the cold collision frequency shift for two photon spectroscopy of Bose-condensed and cold non-Bose-condensed hydrogen is consistent with experimental data. Our…C. W. Gardiner, A. S. Bradley·Aug 28, 2001SaveLearn
Photon Correlation Spectroscopy of a Single Quantum DotWe report photon correlation measurements that allow us to observe unique signatures of biexcitons in a single self-assembled InAs quantum dot. Photon correlation measurements of biexciton emission…A. Kiraz, S. Falth, C. Becher et al.·Aug 28, 2001SaveLearn
Bose-Einstein condensation of metastable helium: some experimental aspectsWe describe our recent realization of BEC using metastable helium. All detection is done with a micruchannel plate which detects the metastables or ions coming from the trapped atom cloud. This…C. I. Westbrook, A. Robert, O. Sirjean et al.·Aug 27, 2001SaveLearn
Structural and electronic properties of an azamacrocycle, C26H18N6We compute the structure of an azamacrocycle, C26H18N6. Two approximatively planar elliptical structures with C2 or CI symmetry are found to be nearly degenerate. The roughly circular conformation…K. Doll, G. Zwicknagl·Aug 27, 2001SaveLearn
Phase transitions at surfaces, edges, and cornersResults of large-scale Monte Carlo simulations of three-dimensional Ising models with edges and corners are reviewed. At the ordinary transition, angle dependent critical exponents are observed,…Michel Pleimling·Aug 27, 2001SaveLearn
Multifractal nature of stock exchange pricesThe multifractal structure of the temporal dependence of the Deutsche Aktienindex (DAX) is analyzed. The q-th order moments of the structure functions and the singular measures are calculated. The…M. Ausloos, K. Ivanova·Aug 24, 2001SaveLearn
Thermodynamics and Kinetics of Folding of a Small PeptideWe study the thermodynamics and kinetics of folding for a small peptide. Our data rely on Monte Carlo simulations where the interactions among all atoms are taken into account. Monte Carlo kinetics…Ulrich H. E. Hansmann, Jose N. Onuchic·Aug 24, 2001SaveLearn
Multifractality of Cloud Base Height ProfilesCloud base height profiles measured with laser ceilometer are studied using multifractal approach. The irregular structure of the signals is a benchmark for nonlinear dynamical processes. A hierarchy…K. Ivanova, N. Gospodinova, H. N. Shirer et al.·Aug 24, 2001SaveLearn
The Dilute Bose-Einstein Condensate with Large Scattering LengthWe study a dilute Bose gas of atoms whose scattering length a is large compared to the range of their interaction. We calculate the energy density of the homogeneous Bose-Einstein condensate to…Eric Braaten, H. -W. Hammer, Thomas Mehen·Aug 23, 2001SaveLearn
"Barchan" dunes in the labWe demonstrate the feasibility of studying dunes in a laboratory experiment. It is shown that an initial sand pile, under a wind flow carrying sand, flattens and gets a shape recalling barchan dunes.…O. Dauchot, F. Lechenault, C. Gasquet et al.·Aug 23, 2001SaveLearn
Impurity and strain effects on the magnetotransport of La1.85Sr0.15Cu(1-y)Zn(y)O4 filmsThe influence of zinc doping and strain related effects on the normal state transport properties(the resistivity, the Hall angle and the orbital magneto- resistance(OMR) is studied in a series of…Marta Z. Cieplak, A. Malinowski, K. Karpinska et al.·Aug 23, 2001SaveLearn
One-dimensional compression of Bose-Einstein condensates by laser-induced dipole-dipole interactionsWe consider a trapped cigar-shaped atomic Bose-Einstein condensate irradiated by a single far-off resonance laser polarized along the cigar axis. The resulting laser induced dipole-dipole…S. Giovanazzi, D. O'Dell, G. Kurizki·Aug 23, 2001SaveLearn
Quantum effects on curve crossing in a Bose-Einstein condensateFormation of atomic pairs by the dissociation of a molecular condensate or by inelastic collisions in an atomic condensate due to a time-dependent curve crossing process is studied beyond the…V. A. Yurovsky, A. Ben-Reuven, P. S. Julienne·Aug 23, 2001SaveLearn
Magnetotransport in the Normal State of La1.85Sr0.15Cu(1-y)Zn(y)O4 FilmsWe have studied the magnetotransport properties in the normal state for a series of La1.85Sr0.15Cu(1-y)Zn(y)O4 films with values of y, between 0 and 0.12. A variable degree of compressive or tensile…A. Malinowski, Marta Z. Cieplak, S. Guha et al.·Aug 23, 2001SaveLearn
Internal transitions of negatively charged magneto-excitons and many body effects in a two-dimensional electron gasSpin-singlet and spin-triplet internal transitions of quasi-two-dimensional, negatively charged magneto-excitons (X-) and their evolution with excess electron density have been studied in GaAs/AlGaAs…H. A. Nickel, T. M. Yeo, A. B. Dzyubenko et al.·Aug 21, 2001SaveLearn
On the Nature of Charge Transport in Quantum-Cascade LasersThe first global quantum simulation of semiconductor-based quantum-cascade lasers is presented. Our three-dimensional approach allows to study in a purely microscopic way the current-voltage…Rita Claudia Iotti, Fausto Rossi·Aug 21, 2001SaveLearn
Electro-optical properties of semiconductor quantum dots: Application to quantum information processingA detailed analysis of the electro-optical response of single as well as coupled semiconductor quantum dots is presented. This is based on a realistic ---i.e., fully tridimensional--- description of…Eliana Biolatti, Irene D'Amico, Paolo Zanardi et al.·Aug 21, 2001SaveLearn