c-axis transport and phenomenology of the pseudo-gap state in Bi2Sr2CaCu2O8+δBi_2Sr_2CaCu_2O_{8+\delta}

We measure and analyze the resistivity of $Bi_2Sr_2CaCu_2O_{8+\delta}$ crystals for different doping $\delta$. We obtain the fraction of carrier $\eta(T,\delta) = n_g/n_{TOT}$ that do not participate to the c-axis conductivity. All the curves $\eta(T,\delta)$ collapse onto a universal curve when plotted against a reduced temperature $x=[T-\Theta(\delta)]/\Delta^{*}(\delta)$. We find that at the superconducting transition $n_g$ is doping independent. We also show that a magnetic field up to 14 T does not affect the degree of localization in the (a,b) planes but widens the temperature range of the x-scaling by suppressing the superconducting phase coherence.Comment: 11 pages, 5 figures, submitted to Phys.Rev.

What is moving in silica at 1 K? A computer study of the low-temperature anomalies

Though the existence of two-level systems (TLS) is widely accepted to explain low temperature anomalies in many physical observables, knowledge about their properties is very rare. For silica which is one of the prototype glass-forming systems we elucidate the properties of the TLS via computer simulations by applying a systematic search algorithm. We get specific information in the configuration space, i.e. about relevant energy scales, the absolute number of TLS and electric dipole moments. Furthermore important insight about the real-space realization of the TLS can be obtained. Comparison with experimental observations is included

Error correcting method and apparatus Patent

Description of error correcting methods for use with digital data computers and apparatus for encoding and decoding digital dat

Charge-Spin Separation in 2D Fermi Systems: Singular Interactions as Modified Commutators, and Solution of 2D Hubbard Model in Bosonized Approximation

The general 2-dimensional fermion system with repulsive interactions (typified by the Hubbard Model) is bosonized, taking into account the finite on-shell forward scattering phase shift derived in earlier papers. By taking this phase shift into account in the bosonic commutation relations a consistent picture emerges showing the charge-spin separation and anomalous exponents of the Luttinger liquid.Comment: Latex file 14 pages. email: [email protected]

Engineering flight and guest pilot evaluation report, phase 2

Prior to the flight evaluation, the two-segment profile capabilities of the DC-8-61 were evaluated and flight procedures were developed in a flight simulator at the UA Flight Training Center in Denver, Colorado. The flight evaluation reported was conducted to determine the validity of the simulation results, further develop the procedures and use of the area navigation system in the terminal area, certify the system for line operation, and obtain evaluations of the system and procedures by a number of pilots from the industry. The full area navigation capabilities of the special equipment installed were developed to provide terminal area guidance for two-segment approaches. The objectives of this evaluation were: (1) perform an engineering flight evaluation sufficient to certify the two-segment system for the six-month in-service evaluation; (2) evaluate the suitability of a modified RNAV system for flying two-segment approaches; and (3) provide evaluation of the two-segment approach by management and line pilots

The Relation of Thermal Fluctuation and Information-Entropy for One-Dimensional Rindler Oscillator

Within the framework of thermo-field-dynamics (TFD), the information-entropies associated with the measurements of position and momentum for one-dimensional Rindler oscillator are derived, and the connection between its information-entropy and thermal fluctuation is obtained. A conclusion is drawn that the thermal fluctuation leads to the loss of information.Comment: 14 pages, 1 figur

Coarse-graining a restricted solid-on-solid model

A procedure suggested by Vvedensky for obtaining continuum equations as the coarse-grained limit of discrete models is applied to the restricted solid-on-solid model with both adsorption and desorption. Using an expansion of the master equation, discrete Langevin equations are derived; these agree quantitatively with direct simulation of the model. From these, a continuum differential equation is derived, and the model is found to exhibit either Edwards-Wilkinson or Kardar-Parisi-Zhang exponents, as expected from symmetry arguments. The coefficients of the resulting continuum equation remain well-defined in the coarse-grained limit.Comment: Accepted for pubication in PR

Quantum Spin Nematic States in Bose-Einstein Condensates

We review some recent results on discrete symmetries and topological order in spinor Bose-Einstein condensates (BECs) of $^{23}Na$. For spin one bosons with two-body scatterings dominated by a total spin equal to two channel, the BECs are in quantum spin nematic states at a low density limit. We study spin correlations in condensates at different limits and analyze hidde$symmetries using a non-perturbative approach developed recently. We further more investigate the influence of hidden$Z_2$ symmetries and U(1) quantum orders in symmetry partially retored states, particularly the effects on topological excitations.Comment: 30 pages, 13 figs included. to appear in Int. Jour. Mod. Phys.

Development and application of the GIM code for the Cyber 203 computer

The GIM computer code for fluid dynamics research was developed. Enhancement of the computer code, implicit algorithm development, turbulence model implementation, chemistry model development, interactive input module coding and wing/body flowfield computation are described. The GIM quasi-parabolic code development was completed, and the code used to compute a number of example cases. Turbulence models, algebraic and differential equations, were added to the basic viscous code. An equilibrium reacting chemistry model and implicit finite difference scheme were also added. Development was completed on the interactive module for generating the input data for GIM. Solutions for inviscid hypersonic flow over a wing/body configuration are also presented