Effects of D-strain, g-strain, and dipolar interactions on EPR linewidths of the molecular magnets Fe8 and Mn12Electron paramagnetic resonance (EPR) measurements on single crystals of the molecular magnets Fe8 and Mn12 reveal complex nonlinearities in the linewidths as functions of energy eigenstate,…Kyungwha Park, M. A. Novotny, N. S. Dalal et al.·Jun 14, 2001SaveLearn
Magnetic field-induced insulating behavior in highly oriented pyrolitic graphiteWe propose an explanation for the apparent semimetal-insulator transition observed in highly oriented pyrolitic graphite in the presence of magnetic field perpendicular to the layers. We show that…D. V. Khveshchenko·Jun 14, 2001SaveLearn
Non-gaussian Noise in Quantum Spin Glasses and Interacting Two-level SystemsWe study a general model for non-gaussian 1/f noise based on an infinite range quantum Ising spin system in the paramagnetic state, or equivalently, interacting two-level classical fluctuators. We…A. K. Nguyen, S. M. Girvin·Jun 14, 2001SaveLearn
Wave Equation for Sound in Fluids with VorticityWe use Clebsch potentials and an action principle to derive a closed system of gauge invariant equations for sound superposed on a general background flow. Our system reduces to the Unruh (1981) and…Santiago Esteban Perez Bergliaffa, Katrina Hibberd, Michael Stone et al.·Jun 13, 2001SaveLearn
Periodically-dressed Bose-Einstein condensates: a superfluid with an anisotropic and variable critical velocityTwo intersecting laser beams can produce a spatially-periodic coupling between two components of an atomic gas and thereby modify the dispersion relation of the gas according to a dressed-state…J. Higbie, D. M. Stamper-Kurn·Jun 13, 2001SaveLearn
Numerical study of quantum percolationWe study the density of states and the optical conductivity of the classical double-exchange model on a site percolated cluster.A. Weiße, H. Fehske·Jun 13, 2001SaveLearn
Evidence for internal field in graphite: A conduction electron spin resonance studyWe report conduction electron spin resonance measurements performed on highly oriented pyrolitic graphite samples between 10 K and 300 K using S (f = 4 GHz), X (f = 9.4 GHz), and Q (f = 34.4 GHz)…M. S. Sercheli, Y. Kopelevich, R. Ricardo da Silva et al.·Jun 12, 2001SaveLearn
Dynamics and Stability of Bose-Einstein Condensates: the Nonlinear Schrodinger Equation with Periodic PotentialThe cubic nonlinear Schrodinger equation with a lattice potential is used to model a periodic dilute gas Bose-Einstein condensate. Both two- and three-dimensional condensates are considered, for…Bernard Deconinck, Bela A. Frigyik, J. Nathan Kutz·Jun 12, 2001SaveLearn
Single ion anisotropy of Mn doped GaAs measured by EPRElectron paramagnetic resonance (EPR) study of MBE grown Mn doped GaAs is presented. The resolved fine structure allows us to evaluate the crystal field parameters of the spin Hamiltonian. The…O. M. Fedorych, E. M. Hankiewicz, Z. Wilamowski et al.·Jun 12, 2001SaveLearn
Dissociation of vertical semiconductor diatomic artificial moleculesWe investigate the dissociation of few-electron circular vertical semiconductor double quantum dot artificial molecules at 0 T as a function of interdot distance. Slight mismatch introduced in the…M. Pi, A. Emperador, M. Barranco et al.·Jun 12, 2001SaveLearn
Charge Transport in Polymer Ion Conductors: a Monte Carlo StudyDiffusion of ions through a fluctuating polymeric host is studied both by Monte Carlo simulation of the complete system dynamics and by dynamic bond percolation (DBP) theory. Comparison of both…O. Durr, W. Dieterich, A. Nitzan·Jun 11, 2001SaveLearn
Model studies of diffusion in glassy and polymer ion conductorsIon-conducting glasses and polymer systems show several characteristic peculiarities in their composition-dependent diffusion properties and in their dynamic response. First we give a brief review of…O. Durr, P. Pendzig, W. Dieterich et al.·Jun 11, 2001SaveLearn
Melt viscosities of lattice polymers using a Kramers potential treatmentKramers relaxation times τK and relaxation times τR and τG for the end-to-end distances and for center of mass diffusion are calculated for dense systems of athermal lattice chains.…O. Durr, H. L. Frisch, W. Dieterich·Jun 11, 2001SaveLearn
Pattern formation in directional solidification under shear flow. I: Linear stability analysis and basic patternsAn asymptotic interface equation for directional solidification near the absolute stabiliy limit is extended by a nonlocal term describing a shear flow parallel to the interface. In the long-wave…Yannick Marietti, Jean-Marc Debierre, Thomas-Michael Bock et al.·Jun 7, 2001SaveLearn
Electron FractionalizationA largely qualitative, and rather idiosyncratic discussion of electron fractionalization in condensed matter physics is presented, including some historical reflections and some speculations…S. A. Kivelson·Jun 7, 2001SaveLearn
Theoretical Considerations of Electrochemical Phase Formation in a Frank-van der Merwe SystemStatic calculation and preliminary kinetic Monte Carlo simulation studies are undertaken for the nucleation and growth on a model system which follows a Frank-van der Merwe mechanism. In the present…M. C. Gimenez, M. G. Del Popolo, E. P. M. Leiva et al.·Jun 6, 2001SaveLearn
Spin-polarized transport in inhomogeneous magnetic semiconductors: theory of magnetic/nonmagnetic p-n junctionsA theory of spin-polarized transport in inhomogeneous magnetic semiconductors is developed and applied to magnetic/nonmagnetic p-n junctions. Several phenomena with possible spintronic applications…Igor Zutic, Jaroslav Fabian, S. Das Sarma·Jun 5, 2001SaveLearn
Photoassisted dynamical transport in multiple quantum wellsWe study the dynamical transport in weakly coupled superlattices in the presence of intense radiation in the THz regime. We derive a general model for the time dependent tunneling current within the…Rosa Lopez, David Sanchez, Gloria Platero·Jun 5, 2001SaveLearn
Spectroscopic and magnetic mirages of impurities in nanoscopic systemsWe present exact results for magnetic impurities in nanoscopic systems with focusing properties. We analyze the spectroscopic and magnetic properties of Kondo, intermediate valence and magnetic…K. Hallberg, A. Correa, C. A. Balseiro·Jun 5, 2001SaveLearn
Critical Point of a Weakly Interacting Two-Dimensional Bose GasWe study the Berezinskii-Kosterlitz-Thouless transition in a weakly interacting 2D quantum Bose gas using the concept of universality and numerical simulations of the classical |ψ|4-model on a…Nikolay Prokof'ev, Oliver Ruebenacker, Boris Svistunov·Jun 5, 2001SaveLearn
Damping and frequency shift in the oscillations of two colliding Bose-Einstein condensatesWe have investigated the center-of-mass oscillations of a Rb87 Bose-Einstein condensate in an elongated magneto-static trap. We start from a trapped condensate and we transfer part of the atoms to…M. Modugno, C. Fort, P. Maddaloni et al.·Jun 5, 2001SaveLearn
Charge redistribution and polarization energy of organic molecular crystalsWe present an approach to electronic polarization in molecular solids treated as a set of quantum systems interacting classically. Individual molecules are dealt with rigorously as quantum-mechanical…E. V. Tsiper, Z. G. Soos·Jun 5, 2001SaveLearn
Efficient Recursion Method for Inverting Overlap MatrixA new O(N) algorithm based on a recursion method, in which the computational effort is proportional to the number of atoms N, is presented for calculating the inverse of an overlap matrix which is…T. Ozaki·Jun 4, 2001SaveLearn
Convergent recursive O(N) calculations for ab initio tight-bindingA theory is presented for a novel recursion method for O(N) ab initio tight-binding calculations. A long-standing problem of generalizing the recursion method to a non-orthogonal basis, which is a…T. Ozaki, K. Terakura·Jun 4, 2001SaveLearn
On the role of dimensionality in many-body theories of magnetic long-range orderStarting from general considerations concerning phase transitions and the many-body problem, a pedagogical introduction to the Mermin-Wagner theorem is given. Particular attention is paid to how the…Axel Gelfert·Jun 3, 2001SaveLearn