A Theory of Magnets with Competing Double Exchange and Superexchange InteractionsWe study the competition between ferromagnetic double exchange (DE) and nearest-neighbour antiferromagnetic exchange in CMR materials. Towards this end, a single site mean field theory is proposed…D. I. Golosov, M. R. Norman, K. Levin·Dec 8, 1997SaveLearn
High frequency magneto-electrodynamics of La(1-x)SrxMnO3 single crystalsThe radio frequency (RF) response of La1-xSrxMnO3 single crystals reveal a variety of features associated with the structural, electronic and magnetic properties of the system. The resonance…H. Srikanth, B. Revcolevschi, S. Sridhar et al.·Dec 8, 1997SaveLearn
Quantum aging in mean-field modelsWe study the real-time dynamics of quantum models with long-range interactions coupled to a heat-bath within the closed-time path-integral formalism. We show that quantum fluctuations depress the…Leticia F. Cugliandolo, Gustavo Lozano·Dec 8, 1997SaveLearn
Asymptotic expansion of the ground state energy of half-filled Hubbard modelThis paper was withdrawn by the author because the results already appeared in PRB 20, 4756 (1979).Minoru Takahashi·Dec 8, 1997SaveLearn
Phonon Squeezed States Generated by Second Order Raman ScatteringWe study squeezed states of phonons, which allow a reduction in the quantum fluctuations of the atomic displacements to below the zero-point quantum noise level of coherent phonon states. We…X. Hu, Franco Nori·Dec 5, 1997SaveLearn
Coulomb effects in a ballistic one-channel S-S-S deviceWe develop a theory of Coulomb oscillations in superconducting devices in the limit of small charging energy EC Δ. We consider a small superconducting grain of finite capacity connected to two…D. A. Ivanov, M. V. Feigel'man·Dec 5, 1997SaveLearn
Why are glass-forming liquids non-Arrhenius?A major mystery of glass-forming liquids is the non-Arrhenius temperature-dependence of the average relaxation time. This paper briefly reviews the classical phenomenological models for this…Jeppe C. Dyre·Dec 5, 1997SaveLearn
Quenched degrees of freedom in symmetric diblock copolymer thin filmsWe study the effect of monomer immobilization (quenching) on the orientation of the lamellae in symmetric diblock copolymer thin films with neutrally wetting surfaces. A small fraction of the…Wilfred H. Tang, Thomas A. Witten·Dec 5, 1997SaveLearn
Scattering Matrix Theory For Nonlinear TransportWe report a scattering matrix theory for dynamic and nonlinear transport in coherent mesoscopic conductors. In general this theory allows predictions of low frequency linear dynamic conductance, as…Zhong-shui Ma, Jian Wang, Hong Guo·Dec 5, 1997SaveLearn
Weakly Nonlinear AC Response: Theory and ApplicationWe report a microscopic and general theoretical formalism for electrical response which is appropriate for both DC and AC weakly nonlinear quantum transport. The formalism emphasizes the…Zhong-shui Ma, Jian Wang, Hong Guo·Dec 5, 1997SaveLearn
Mobility and Reactivity of Discrete BreathersBreathers may be mobile close to an instability threshold where the frequency of a pinning mode vanishes. The translation mode is a marginal mode that is a solution of the linearized (Hill) equation…S. Aubry, T. Cretegny·Dec 3, 1997SaveLearn
Analytic Solution of a Relativistic Two-dimensional Hydrogen-like Atom in a Constant Magnetic FieldWe obtain exact solutions of the Klein-Gordon and Pauli Schroedinger equations for a two-dimensional hydrogen-like atom in the presence of a constant magnetic field. Analytic solutions for the energy…Victor M. Villalba, Ramiro Pino·Dec 3, 1997SaveLearn
Gravitational dependence of contact angle hysteresis for a solid defect pinning a liquid-vapor interfaceWe study the case of contact angle hysteresis, when a solid defect is quasi-statically pulled out and pushed into a liquid, in the presence of gravity. We solve the problem analytically in an…Jorgen Vitting Andersen, Henrik Jeldtoft Jensen·Dec 3, 1997SaveLearn
Photon Assisted Electric Field Domains in Semiconductor Doped SuperlatticesWe study photon-assisted tunneling (PAT) through weakly-coupled doped semiconductor superlattices (SL's) in the high voltage regime. A self-consistent model which treats the Coulomb interaction…R. Aguado, G. Platero·Dec 3, 1997SaveLearn
Adsorbate Interactions of CO Chemisorbed on Pt(111)We show that the observed repulsive interaction between CO molecules on the Pt(111) surface can be explained by the coupling of the Pt--CO separation with Pt-Pt coordinates in the substrate. The…R. Brako, D. Sokcevic·Dec 2, 1997SaveLearn
Boundary interactions changing operators and dynamical correlations in quantum impurity problemsRecent developments have made possible the computation of equilibrium dynamical correlators in quantum impurity problems. In many situations however, one is rather interested in correlators subject…F. Lesage, H. Saleur·Dec 1, 1997SaveLearn
The Quantum Mechanical Potential for the Prime NumbersA simple criterion is derived in order that a number sequence Sn is a permitted spectrum of a quantized system. The sequence of the prime numbers fulfils the criterion and the corresponding…G. Mussardo·Dec 1, 1997SaveLearn
Three-loop renormalization group analysis of a complex model with stable fixed point: Critical exponents up to ε3 and ε4The complete analysis of a model with three quartic coupling constants associated with an O(2N)--symmetric, a cubic, and a tetragonal interactions is carried out within the three-loop approximation…Andrei Mudrov, Konstantin Varnashev·Nov 30, 1997SaveLearn
Magnetic moment interaction in the anyon superconductorMagnetic moment interaction is shown to play a defining role in the magnetic properties of anyon superconductors. The necessary condition for the existence of the Meissner effect is found.M. Eliashvili, G. Tsitsishvili·Nov 28, 1997SaveLearn
Finite-Size Effects in the ϕ4 Field Theory Above the Upper Critical DimensionWe demonstrate that the standard O(n) symmetric ϕ4 field theory does not correctly describe the leading finite-size effects near the critical point of spin systems on a d-dimensional lattice…X. S. Chen, V. Dohm·Nov 27, 1997SaveLearn
Statistical mechanics of warm and cold unfolding in proteinsWe present a statistical mechanics treatment of the stability of globular proteins which takes explicitly into account the coupling between the protein and water degrees of freedom. This allows us to…Alex Hansen, Mogens H. Jensen, Kim Sneppen et al.·Nov 27, 1997SaveLearn
What Determines Inhomogeneous Line Widths in Semiconductor Microcavities?Microcavity inhomogeneous line widths are calculated numerically using a microscopic two dimensional model of the polariton interaction with quantum well disorder. The calculations show show that in…D. M. Whittaker·Nov 27, 1997SaveLearn
Ab initio calculation of the potential energy surface for the dissociation of H2 on the sulfur covered Pd(100) surfaceThe presence of sulfur atoms on the Pd(100) surface is known to hinder the dissociative adsorption of hydrogen. Using density-functional theory and the full-potential linear augmented plane-wave…C. M. Wei, A. Gross, M. Scheffler·Nov 27, 1997SaveLearn
Hierarchical Structure of Azbel-Hofstader Problem: Strings and loose ends of Bethe AnsatzWe present numerical evidence that solutions of the Bethe Ansatz equations for a Bloch particle in an incommensurate magnetic field (Azbel-Hofstadter or AH model), consist of…A. G. Abanov, J. C. Talstra, P. B. Wiegmann·Nov 26, 1997SaveLearn
λ-transition in low dimensional systems with SUq(2) symmetryWe show that SUq(2) invariant systems in one and two dimensions exhibit Bose-Einstein condensation for q >1. For these systems there is a λ-transition at the critical temperature. The critical…Marcelo R. Ubriaco·Nov 26, 1997SaveLearn