Crossover from nonadiabatic to adiabatic electron transfer reactions: Multilevel blocking Monte Carlo simulationsThe crossover from nonadiabatic to adiabatic electron transfer has been theoretically studied under a spin-boson model (dissipative two-state system) description. We present numerically exact data…L. Muehlbacher, R. Egger·May 19, 2002SaveLearn
Phonon anomaly at the charge ordering transition in 1T-TaS2The infrared reflectance of the transition metal chalcogenide 1T-TaS2 has been measured at temperatures from 30K to 360K over 30-45,000cm-1 (4meV-5.5eV). The optical conductivity was obtained by…L. V. Gasparov, K. G. Brown, A. C. Wint et al.·May 18, 2002SaveLearn
Formation of a Matter-Wave Bright SolitonWe report the production of matter-wave solitons in an ultracold lithium 7 gas. The effective interaction between atoms in a Bose-Einstein condensate is tuned with a Feshbach resonance from repulsive…L. Khaykovich, F. Schreck, G. Ferrari et al.·May 17, 2002SaveLearn
Magnetization plateaux in a generalised ladder modelA spin-1/2 antiferromagnetic(AFM) generalised ladder model is constructed which consists of four-spin plaquettes, coupled through weaker exchange interactions, to two-spin rungs. In an extended…Emily Chattopadhyay, Indrani Bose·May 17, 2002SaveLearn
Momentum distribution of the uniform electron gas: improved parametrization and exact limits of the cumulant expansionThe momentum distribution of the unpolarized uniform electron gas in its Fermi-liquid regime, n(k,rs), with the momenta k measured in units of the Fermi wave number kF and with the density…Paola Gori-Giorgi, Paul Ziesche·May 16, 2002SaveLearn
Manipulation of the Spin Memory of Electrons in n-GaAsWe report on the optical manipulation of the electron spin relaxation time in a GaAs based heterostructure. Experimental and theoretical study shows that the average electron spin relaxes through…R. I. Dzhioev, V. L. Korenev, I. A. Merkulov et al.·May 16, 2002SaveLearn
Electronic polarization at surfaces and thin films of organic molecular crystals: PTCDAThe electronic polarization energies, P = (P+) + (P-), of a PTCDA (perylenetetracarboxylic acid dianhydride) cation and anion in a crystalline thin film on a metallic substrate are computed and…E. V. Tsiper, Z. G. Soos, W. Gao et al.·May 16, 2002SaveLearn
Theory of spin-polarized bipolar transport in magnetic p-n junctionsThe interplay between spin and charge transport in electrically and magnetically inhomogeneous semiconductor systems is investigated theoretically. In particular, the theory of spin-polarized bipolar…Jaroslav Fabian, Igor Zutic, S. Das Sarma·May 16, 2002SaveLearn
Statistical correlation for the composite BosonIt is well known that the particles in a beam of Boson obeying Bose-Einstein statistics tend to cluster (bunching effect), while the particles in a degenerate beam of Fermion obeying Fermi-Dirac…Baigeng Wang, Jian Wang·May 16, 2002SaveLearn
Critical nonlinear Schroedinger equations with and without harmonic potentialWe use a change of variables that turns the critical nonlinear Schroedinger equation into the critical nonlinear Schroedinger equation with isotropic harmonic potential, in any space dimension. This…Remi Carles·May 15, 2002SaveLearn
Comparing schemes of displacement detection and subharmonic generation in nanomachined mechanical resonatorsWe present measurements on nanomechanical resonators operating in the radio frequency range. We apply a setup which allows the comparison of two schemes of displacement detection for mechanical…Florian W. Beil, Laura Pescini, Eva Höhberger et al.·May 15, 2002SaveLearn
An introduction to symmetric spacesRecently, the theory of symmetric spaces has come to play an increased role in the physics of integrable systems and in quantum transport problems. In addition, it provides a classification of random…Ulrika Magnea·May 14, 2002SaveLearn
Number--conserving model for boson pairingAn independent pair ansatz is developed for the many body wavefunction of dilute Bose systems. The pair correlation is optimized by minimizing the expectation value of the full hamiltonian (rather…S. Fantoni, T. M. Nguyen, A. Sarsa et al.·May 14, 2002SaveLearn
Quantum Disentanglement in Long-range Orders and Spontaneous Symmetry BreakingWe investigate the nature of quantum entanglement in long-range orders and spontaneous symmetry breaking. It is shown that diminishing of entanglement between the condensate mode and the rest of the…Yu Shi·May 13, 2002SaveLearn
Comment on "Are financial crashes predictable?"Comment on "Are financial crashes predictable?", L. Laloux, M. Potters, R. Cont, J.P Aguilar and J.-P. Bouchaud, Europhys. Lett. 45, 1-5 (1999)Anders Johansen·May 13, 2002SaveLearn
A Comment on the beta-expansion of s=1/2 and s=1 Ising ModelsThe purpose of the present work is to apply the method recently developed in reference [chainm] to the spin-1 Ising chain, showing how to obtain analytical β-expansions of thermodynamical…Winder A. Moura-Melo, Onofre Rojas, E. V. Correa Silva et al.·May 13, 2002SaveLearn
Formation of a molecular Bose-Einstein condensate and an entangled atomic gas by Feshbach resonanceProcesses of association in an atomic Bose-Einstein condensate, and dissociation of the resulting molecular condensate, due to Feshbach resonance in a time-dependent magnetic field, are analyzed…V. A. Yurovsky, A. Ben-Reuven·May 13, 2002SaveLearn
How Structure Affects Power-Law BehaviorComplex systems contain a lot of individuals and some interactions between them. The structure of interactions can be modeled to be a network: nodes represent individuals and links to be interaction…Jing Han, Wei Li·May 13, 2002SaveLearn
Producing Bose condensates using optical latticesWe relate the entropies of ensembles of atoms in optical lattices to atoms in simple traps. We then determine which ensembles of lattice-bound atoms will adiabatically transform into a Bose…Maxim Olshanii, David Weiss·May 12, 2002SaveLearn
Dynamical analysis of S&P500 momentumThe dynamics of the S&P500 price signal is studied using a moving average technique. Particular attention is paid to intersections of two moving averages with different time horizons. The…K. Ivanova, L. T. Wille·May 11, 2002SaveLearn
Influence of a low magnetic field on the thermal diffusivity of Bi-2212The thermal diffusivity of a Bi-2212 polycrystalline sample has been measured under a 1T magnetic field applied perpendicularly to the heat flux. The magnetic contribution to the heat carrier mean…S. Dorbolo, M. Ausloos·May 11, 2002SaveLearn
Continuum in the Excitation Spectrum of the S=1 Compound CsNiCl3Recent neutron scattering experiments on CsNiCl3 reveal some features which are not well described by the nonlinear sigma model nor by numerical simulations on isolated S=1 spin chains. In…E. Ercolessi, G. Morandi, M. Roncaglia·May 11, 2002SaveLearn
Stability of the two-dimensional Bose gases in the resonant regimeWe consider a two-dimensional Bose gas formed in a planar atomic trap in conditions where the two-dimensional scattering length exceeds all other microscopic length scales in the system and,…Ludovic Pricoupenko, Maxim Olshanii·May 10, 2002SaveLearn
Modelling charge self-trapping in wide-gap dielectrics: Localization problem in local density functionalsWe discuss the adiabatic self-trapping of small polarons within the density functional theory (DFT). In particular, we carried out plane-wave pseudo-potential calculations of the triplet exciton in…Jacob L. Gavartin, Peter V. Sushko, Alexander L. Shluger·May 10, 2002SaveLearn
Diffraction in left-handed materials and theory of Veselago lensA theory of diffraction in the system consisting of the left-handed and the right-handed materials is proposed. The theory is based upon the Huygens's principle and the Kirchhoff's integral…A. L. Pokrovsky, A. L. Efros·May 10, 2002SaveLearn