Absence of string order in the anisotropic S=2 Heisenberg antiferromagnetWe study an AFM Heisenberg S=2 quantum spin chain at T=0 with both interaction and on-site anisotropy, H = Σi 1/2(S+iS-i+1+S-iS+i+1)…H. Aschauer, U. Schollwoeck·Feb 18, 1998SaveLearn
Volatility and Agent Adaptability in a Self-Organizing MarketWe present results for the so-called `bar-attendance' model of market behavior: p adaptive agents, each possessing n prediction rules chosen randomly from a pool, attempt to attend a bar…N. F. Johnson, S. Jarvis, R. Jonson et al.·Feb 17, 1998SaveLearn
4/3-Law of Granular Particles Flowing through a Vertical PipeDensity waves of granular material (sand) flowing through a vertical pipe have been investigated. Clear density waves emerge when the cock attached to bottom end of the pipe is closed. The FFT power…Osamu Moriyama, Naoya Kuroiwa, Mitsugu Matsushita et al.·Feb 17, 1998SaveLearn
Anomalous temperature dependence of resistivity in quasi-one-dimensional conductors in a strong magnetic fieldWe present a heuristic, semiphenomenological model of the anomalous temperature (T) dependence of resistivity Rxx recently observed experimentally in the quasi-one-dimensional (Q1D) organic…Anatoley T. Zheleznyak, Victor M. Yakovenko·Feb 16, 1998SaveLearn
Phase diagram of second layer of helium adsorbed on graphiteUsing realistic helium-helium and helium-graphite interactions and the path integral Monte Carlo method, we are able to identify the gas, superfluid liquid, commensurate-solid, and…Marlon Pierce, Efstratios Manousakis·Feb 16, 1998SaveLearn
Tunneling Times and "Superluminal" Tunneling: A brief ReviewIn the First Part of this paper [that was submitted for pub. in 1991 and appeared in print in Phys. Reports 214 (1992) 339] we critically review the main theoretical definitions and calculations of…Vladislav S. Olkhovsky, Erasmo Recami·Feb 15, 1998SaveLearn
Strong Coupling Approach to the d-p Model on the Basis of Fermi Liquid TheoryWe study the superconducting transition temperature Tc of the bilayer d-p model with dx2-y2-wavelike attractive interaction based on the formalism first employed by Nozières and…Shigeru Koikegami, Kosaku Yamada·Feb 14, 1998SaveLearn
Quantum liquids of particles with generalized statisticsWe propose a phenomenological approach to quantum liquids of particles obeying generalized statistics of a fermionic type, in the spirit of the Landau Fermi liquid theory. The approach is developed…Serguei B. Isakov·Feb 13, 1998SaveLearn
Antiferromagnetic interlayer exchange coupling across an amorphous metallic spacer layerBy means of magneto-optical Kerr effect we observe for the first time antiferromagnetic coupling between ferromagnetic layers across an amorphous metallic spacer layer. Biquadratic coupling occurs at…D. E. Buergler, D. M. Schaller, C. M. Schmidt et al.·Feb 13, 1998SaveLearn
The antiferromagnetic spin 1/2 chain with competing dimers and plaquettes: Numerical versus exact resultsWe examine the ground state and the excitations of an one-dimensional Heisenberg spin 1/2 antiferromagnet with alternating dimers and four-spin plaquettes (dimer-plaquette chain). The properties of…J. Richter, N. B. Ivanov, J. Schulenburg·Feb 13, 1998SaveLearn
Formation of a Heavy-Fermion State in the 2D Periodic Anderson ModelWe study the formation of a heavy-fermion state in the 2D periodic Anerson model. For U=2, the density of states, imaginary part of the self-energy and effective magnetic moment all indicate the…Bumsoo Kyung·Feb 13, 1998SaveLearn
Theory of Electric Field-Induced Photoluminescence Quenching in Disordered Molecular SolidsThe dynamics of excitons in disordered molecular solids is studied theoretically, taking into account migration between different sites, recombination, and dissociation into free charge carriers in…M. C. J. M. Vissenberg, M. J. M. de Jong·Feb 12, 1998SaveLearn
Theory of the field-effect mobility in amorphous organic transistorsThe field-effect mobility in an organic thin-film transistor is studied theoretically. From a percolation model of hopping between localized states and a transistor model an analytic expression for…M. C. J. M. Vissenberg, M. Matters·Feb 12, 1998SaveLearn
Universal behaviors in granular flows and traffic flowsWe review the current understanding on universal behaviors in granular flows through a vertical pipe and traffic flows. We carry out weakly nonlinear analysis of a model for traffic flows based on…Hisao Hayakawa, Ken Nakanishi·Feb 12, 1998SaveLearn
Precursors of Antiferromagnetic and Hubbard Bands in the 2D Hubbard ModelWe formulate a theory to the 2D Hubbard model in a framework free of finite size effect and numerical analytical continuation, yet containing the essential features of the 2D Hubbard model, i.e., the…Bumsoo Kyung·Feb 11, 1998SaveLearn
Tempi di Tunnelling (Tunneling Times)In this review (in Italian) we critically and detaily examine various definitions existing in the literature for the tunnelling times: namely, the phase-time; the centroid-based times; the Buttiker…Giuseppe Privitera, Erasmo Recami, Vladislav S. Olkhovsky·Feb 11, 1998SaveLearn
Concentration Dependence of the Effective Mass of He-3 Atoms in He-3/He-4 MixturesRecent measurements by Yorozu et al. (S. Yorozu, H. Fukuyama, and H. Ishimoto, Phys. Rev. B 48, 9660 (1993)) as well as by Simons and Mueller (R. Simons and R. M. Mueller, Czhechoslowak Journal of…E. Krotscheck, M. Saarela, K. Schoerkhuber et al.·Feb 11, 1998SaveLearn
Structure and far-infrared edge modes of quantum antidots at zero magnetic fieldWe have investigated edge modes of different multipolarity sustained by quantum antidots at zero magnetic field. The ground state of the antidot is described within a local density functional…Agusti Emperador, Marti Pi, Manuel Barranco et al.·Feb 11, 1998SaveLearn
Ferromagnetism in a Hubbard model for an atomic quantum wire: a realization of flat-band magnetism from even-membered ringsWe have examined a Hubbard model on a chain of squares, which was proposed by Yajima et al as a model of an atomic quantum wire As/Si(100), to show that the flat-band ferromagnetism according to a…R. Arita, K. Kuroki, H. Aoki et al.·Feb 10, 1998SaveLearn
Photodissociation in Quantum Chaotic Systems: Random Matrix Theory of Cross-Section FluctuationsUsing the random matrix description of open quantum chaotic systems we calculate in closed form the universal autocorrelation function and the probability distribution of the total photodissociation…Yan V. Fyodorov, Yoram Alhassid·Feb 10, 1998SaveLearn
Axial anomaly in 3He-A: Simulation of baryogenesis and generation of primordial magnetic field in Manchester and HelsinkiThe gapless fermionic excitations in superfluid 3He-A have a "relativistic" spectrum close to the gap nodes. They are the counterpart of the chiral particles (left-handed and right-handed) in…G. E. Volovik·Feb 9, 1998SaveLearn
Disordered XY models and Coulomb gases: renormalization via traveling wavesWe present a novel RG approach to 2D random XY models using direct and replicated Coulomb gas methods. By including fusion of environments (charge fusion in the replicated CG) it follows the…David Carpentier, Pierre Le Doussal·Feb 8, 1998SaveLearn
Supersymmetry in models with strong on-site Coulomb repulsion - application to t-J modelA supersymmetric way of imposing the constraint of no double occupancy in models with strong on-site Coulomb repulsion is presented in this paper. In this formulation the physical operators in the…T. K. Ng, Chi-Ho Cheng·Feb 7, 1998SaveLearn
Spin polaron damping in the spin-fermion model for cuprate superconductorsA self-consistent, spin rotational invariant Green's function procedure has been developed to calculate the spectral function of carrier excitations in the spin-fermion model for the CuO2 plane.…R. O. Kuzian, R. Hayn, A. F. Barabanov et al.·Feb 6, 1998SaveLearn
Magnetic Properties of Dilute Alloys: Equations for Magnetization and its Structural FluctuationsThe dilute Heisenberg ferromagnet is studied taking into account fluctuations of magnetization caused by disorder. A self-consistent system of equations for magnetization and its mean quadratic…I. Vakarchuk, V. Tkachuk, T. Kuliy·Feb 6, 1998SaveLearn