Peierls instability of vortex tubesUsing results of Goldstone and Jaffe, we discuss the possibility of a low temperature instability of vortex tubes to a `folded' state, driven by the coupling to the normal electron states inside…J. P. Bouchaud·Jul 11, 1997SaveLearn
Bose-Einstein condensation of a quantum group gasWe study the Bose-Einstein condensation of a gas with SUq(2) symmetry. We show, in the thermodynamic limit, that the boson interactions introduced by the quantum group symmetries enhance…Marcelo R. Ubriaco·Jul 10, 1997SaveLearn
Fragmentation Phase Transition in Atomic Clusters IV -- Liquid-gas transition in finite metal clusters and in the bulk --Within the micro-canonical ensemble phase transitions of first order can be identified without invoking the thermodynamic limit. We show for the liquid-gas transition of sodium, potassium, and iron…D. H. E. Gross, M. E. Madjet·Jul 10, 1997SaveLearn
Frictional drag between quantum wells mediated by phonon exchangeWe use the Kubo formalism to evaluate the contribution of acoustic phonon exchange to the frictional drag between nearby two-dimensional electron systems. In the case of free phonons, we find a…Martin Bonsager, Karsten Flensberg, Ben Yu-Kuang Hu et al.·Jul 10, 1997SaveLearn
Restoration of Isotropy for Spin ModelsUsing real-space renormalisation techniques we analyse the Ising model on a Sierpiński gasket with anisotropic microscopic couplings, and observe a restoration of isotropy on macroscopic scales. In…D. C. Brody, A. Ritz·Jul 10, 1997SaveLearn
Effect of interchain coupling on conducting polymer luminescence: excimers in derivatives of poly(phenylene vinylene)Optical excitation of a chain in a polymer film may result in formation of an excimer, a superposition of on-chain excitons and charge-transfer excitons on the originally excited chain and a…M. W. Wu, E. M. Conwell·Jul 9, 1997SaveLearn
Calculation of Giant Magnetoresistance in Laterally Confined MultilayersWe have studied the Giant Magnetoresistance (GMR) for laterally confined multilayers, e.g., layers of wires, using the classical Boltzmann equation in the current-in-plane (CIP) geometry. For…Kingshuk Majumdar, Jian Chen, Selman Hershfield·Jul 8, 1997SaveLearn
Nonequilibrium Magnetization Dynamics of NickelUltrafast magnetization dynamics of nickel has been studied for different degrees of electronic excitation, using pump-probe second-harmonic generation with 150 fs/800 nm laser pulses of various…J. Hohlfeld, E. Matthias, R. Knorren et al.·Jul 8, 1997SaveLearn
Dynamical Effective Medium Theory for Quantum Spins and MultipolesA dynamical effective medium theory is presented for quantum spins and higher multipoles such as quadrupole moments. The theory is a generalization of the spherical model approximation for the Ising…Yoshio Kuramoto, Noboru Fukushima·Jul 8, 1997SaveLearn
Photoluminescence signatures of negatively charged magnetoexcitonsThe negatively charged quasi-two-dimensional exciton (X-) is studied numerically in the presence of a uniform B-field and various in-plane confinements. The corresponding photoluminescence (PL)…J. R. Chapman, N. F. Johnson, V. N. Nicopoulos·Jul 7, 1997SaveLearn
Exchange-correlation potential for Current Density Functional Theory of frequency dependent linear responseThe dynamical, long-wavelength longitudinal and transverse exchange-correlation potentials for a homogeneous electron gas are evaluated in a microscopic model based on an approximate decoupling of…S. Conti, R. Nifosi', M P Tosi·Jul 6, 1997SaveLearn
First and second sound in a uniform Bose gasWe have recently derived two-fluid hydrodynamic equations for a trapped weakly-interacting Bose gas. In this paper, we use these equations to discuss first and second sound in a uniform Bose gas.…A. Griffin, E. Zaremba·Jul 5, 1997SaveLearn
λ-Type phase transition for a weakly interacting bose gasA mechanism generating a λ-type behavior in the specific heat of a Bose gas near the critical temperature Tc is discussed. It is shown to work for a general class of quasiparticle spectra, and…I. Cabrera, H. Perez Rojas·Jul 3, 1997SaveLearn
Resonant Optical Nonlinearity of Conjugated PolymersWhen the energy of a pump wave is in resonance with the exciton creation energy, the electric susceptibility of a conjugated polymer in response to the probe wave is altered by the exciton gas. In…Ming-Che Chang, Hsin-Fei Meng·Jul 3, 1997SaveLearn
Transverse Spin Diffusion in a Dilute Spin-Polarized Degenerate Fermi GasWe re-examine the calculation of the transverse spin-diffusion coefficient in a dilute degenerate spin-polarized Fermi gas, for the case of s-wave scattering. The special feature of this limit is…Denis I. Golosov, Andrei E. Ruckenstein·Jul 2, 1997SaveLearn
Reflection Scattering Matrix of the Ising Model in a Random Boundary Magnetic FieldThe physical properties induced by a quenched surface magnetic field in the Ising model are investigated by means of boundary quantum field theory in replica space. Exact boundary scattering…A. De Martino, M. Moriconi, G. Mussardo·Jul 2, 1997SaveLearn
The Theory of SNOM: A Novel ApproachIn this paper we consider the application of electromagnetic theory to the analysis of the Scanning Near-field Optical Microscope (SNOM) in order to predict experimentally observable quantities such…A. J. Ward, J. B. Pendry·Jul 2, 1997SaveLearn
Vanishing of the negative-sign problem of quantum Monte Carlo simulations in one-dimensional frustrated spin systemsThe negative-sign problem in one-dimensional frustrated quantum spin systems is solved. We can remove negative signs of the local Boltzmann weights by using a dimer basis that has the spin-reversal…Tota Nakamura·Jul 2, 1997SaveLearn
Object orientation and visualization of physics in two dimensionsWe present a generalized framework for cellular/lattice based visualizations in two dimensions based on state of the art computing abstractions. Our implementation takes the form of a library of…Mark Burgess, Haarek Haugerud, Are Strandlie·Jul 1, 1997SaveLearn
Eigenvalue distribution of large random matrices, from one matrix to several coupled matricesIt has been observed that the statistical distribution of the eigenvalues of random matrices possesses universal properties, independent of the probability law of the stochastic matrix. In this…B. Eynard·Jul 1, 1997SaveLearn
Observation of the e/3 Fractionally Charged Laughlin QuasiparticlesThe existence of fractional charges carrying the current is experimentally demonstrated. Using a 2-D electron system in high magnetic field, we measure the shot noise associated with tunneling in the…L. Saminadayar, D. C. Glattli, Y. Jin et al.·Jun 30, 1997SaveLearn
Time-dependent density functional theory beyond the adiabatic local density approximationIn the current density functional theory of linear and nonlinear time-dependent phenomena, the treatment of exchange and correlation beyond the level of the adiabatic local density approximation is…G. Vignale, C. A. Ullrich, S. Conti·Jun 30, 1997SaveLearn
Coupled Cluster Treatment of the XY modelWe study quantum spin systems in the 1D, 2D square and 3D cubic lattices with nearest-neighbour XY exchange. We use the coupled-cluster method (CCM) to calculate the ground-state energy, the T=0…D. J. J. Farnell, S. E. Krueger, J. B. Parkinson·Jun 30, 1997SaveLearn
Peculiarity of the Coulombic Criticality ?We indicate that Coulombic systems could correspond to Wilson effective Hamiltonians similar to that of the ordinary (nonionic) fluids but with a negative ϕ4-coefficient. In that case, solving the…N. V. Brilliantov, J. P. Valleau, C. Bagnuls et al.·Jun 30, 1997SaveLearn
An Ultimate Frustration in Classical-Lattice Gas ModelsWe constructed an uncountable family of classical lattice-gas models with unique ground-state measures which are not uniquely ergodic measures of any tiling system, or more generally, of any system…Jacek Miekisz·Jun 30, 1997SaveLearn