76,974 research outputs found
c-axis transport and phenomenology of the pseudo-gap state in
We measure and analyze the resistivity of
crystals for different doping . We obtain the fraction of carrier
that do not participate to the c-axis
conductivity. All the curves collapse onto a universal curve
when plotted against a reduced temperature
. We find that at the superconducting
transition 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 . 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 hiddeZ_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
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