9,600 research outputs found
On the Harmonic approximation for large Josephson junction coupling charge qubits
We revisit the harmonic approximation (HA) for a large Josephson junction
interacting with some charge qubits through the variational approach for the
quantum dynamics of the junction-qubit coupling system. By making use of
numerical calculation and analytical treatment, the conditions under which HA
works well can be precisely presented to control the parameters implementing
the two-qubit quantum logical gate through the couplings to the large junction
with harmonic oscillator (HO) Hamiltonian.Comment: 7 pages, 3 figure
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The relationship of the big picture appraisal questionnaire with measures of emotion regulation style
Big picture appraisal entails viewing difficult situations and one’s reactions to them in terms of a larger context. The purpose of this study was to examine how people who score high or low on a trait measure of big picture thinking differ on a measure of distress and on several other emotion regulation measures. Additionally, whether any of the relationships with big picture thinking might be moderated by sex was addressed. The Big Picture Appraisal Questionnaire (BPAQ, Gill, 2013) showed a weak relationship with social desirability, and moderate to high correlations with emotional restriction as measured by the Affective Control Scale (ACS, Williams, 1997), and with the emotion processing and emotion expression scales of the Emotional Approach Coping Scales (EACS, Stanton, 2000). The correlation between the BPAQ and the Brief Symptom Inventory – 18 (BSI, Derogatis, 1983) was not significant but it is expected that a relationship between these constructs might be found if examined in the presence of life stressors. Lastly, females scored significantly higher than males on the BPAQ. While sex did not significantly moderate the relationship between the BPAQ and other emotion regulation variables, there was a trend toward moderation in the relationship between the ACS (emotional restriction) and the BPAQ, with females, but not males showing a significant relationship between these measures.Educational Psycholog
Low-Temperature Long-Time Simulations of Ising Ferromagnets using the Monte Carlo with Absorbing Markov Chains method
The Monte Carlo with Absorbing Markov Chains (MCAMC) method is introduced.
This method is a generalization of the rejection-free method known as the
-fold way. The MCAMC algorithm is applied to the study of the very
low-temperature properties of the lifetime of the metastable state of Ising
ferromagnets. This is done both for square-lattice and cubic-lattice
nearest-neighbor models. Comparison is made with exact low-temperature
predictions, in particular the low-temperature predictions that the metastable
lifetime is discontinuous at particular values of the field. This discontinuity
for the square lattice is not seen in finite-temperatures studies. For the
cubic lattice, it is shown that these `exact predictions' are incorrect near
the fields where there are discontinuities. The low-temperature formula must be
modified and the corrected low-temperature predictions are not discontinuous in
the energy of the nucleating droplet.Comment: Submitted to Computer Physics Communicatinos, for proceedings of the
Conference CCP2001, 4 figure
Particular Solutions for Axisymmetric Helmholtz-Type Operators
In this paper, we consider the solution of the axisymmetric heat equation with axisymmetric data in an axisymmetric domain in R-3. To solve this problem, we remove the time-dependence by various transform or time-stepping methods. This converts the problem to one of a sequence of modified inhomogeneous Helmholtz equations. Generalizing previous work, we consider solving these equations by boundary-type methods. In order to do this, one needs to subtract off a particular solution, so that one obtains a sequence of modified homogeneous Helmholtz equations. We do this by modifying the usual Dual Reciprocity Method (DRM) and approximating the right-hand sides by Fourier-polynomials or bivariate polynomials. This inevitably leads to analytical solving a sequence of ordinary differential equations (ODEs.) The analytic formulas and their precision are checked using MATHEMATICA. In fact, by using an infinite precision technique, the particular solutions can be obtained with infinite precision themselves. This work will form the basis for numerical algorithms for solving axisymmetric heat equation. (C) 2005 Elsevier Ltd. All rights reserved
Test of Universality in Anisotropic 3D Ising Model
Chen and Dohm predicted theoretically in 2004 that the widely believed
universality principle is violated in the Ising model on the simple cubic
lattice with more than only six nearest neighbours. Schulte and Drope by Monte
Carlo simulations found such violation, but not in the predicted direction.
Selke and Shchur tested the square lattice. Here we check only this
universality for the susceptibility ratio near the critical point. For this
purpose we study first the standard Ising model on a simple cubic lattice with
six nearest neighbours, then with six nearest and twelve next-nearest
neighbours, and compare the results with the Chen-Dohm lattice of six nearest
neighbours and only half of the twelve next-nearest neighbours. We do not
confirm the violation of universality found by Schulte and Drope in the
susceptibility ratio.Comment: 6 pages including 4 figures, Physica A, in pres
Simulation of Photonic Band Gaps in Metal Rod Lattices for Microwave Applications
We have derived the global band gaps for general two-dimensional (2D) photonic band gap (PBG) structures formed by square or triangular arrays of metal posts. Such PBG structures have many promising applications in active and passive devices at microwave, millimeter wave and higher frequencies. A coordinate-space, finite-difference code, called the photonic band gap structure simulator (PBGSS), was developed to calculate complete dispersion curves for lattices for a series of values of the ratio of the post radius (a) to the post spacing (b). The fundamental and higher frequency global photonic band gaps were determined numerically. These universal curves should prove useful in PBG cavity design. In addition, for very long wavelengths, where the numerical methods of the PBGSS code are difficult, dispersion curves were derived for the TM mode by an approximate, quasi-static approach. Results of this approach agree well with the PBGSS code for a/b < 0.1. The present results are compared with experimental data for TE and TM mode PBG resonators built at MIT and the agreement is found to be very good
Unparticle Physics in the Moller Scattering
We investigate the virtual effects of vector unparticles in the Moller
scattering. We derive the analytic expression for scattering amplitudes with
unpolarized beams. We obtain 95% confidence level limits on the unparticle
couplings and with integrated luminosity of
and and 500 GeV energies. We show
that limits on are more sensitive than .Comment: 10 pages, 5 figures, 4 table
Surface tension of the isotropic-nematic interface
We present the first calculations of the pressure tensor profile in the
vicinity of the planar interface between isotropic liquid and nematic liquid
crystal, using Onsager's density functional theory and computer simulation.
When the liquid crystal director is aligned parallel to the interface, the
situation of lowest free energy, there is a large tension on the nematic side
of the interface and a small compressive region on the isotropic side. By
contrast, for perpendicular alignment, the tension is on the isotropic side.
There is excellent agreement between theory and simulation both in the forms of
the pressure tensor profiles, and the values of the surface tension.Comment: Minor changes; to appear in Phys. Rev.
Piecewise continuous partition function method in the theory of wave perturbations of inhomogeneous gas
The problem of wave disturbance propagation in rarefied gas in gravity field
is explored. The system of hydrodynamic-type equations for a stratified gas in
gravity field is derived from BGK equation by method of piecewise continuous
partition function. The obtained system of the equations generalizes the
Navier-Stokes at arbitrary density (Knudsen numbers). The verification of the
model is made for a limiting case of a homogeneous medium. Results are in the
good agreement with experiment and former theories at arbitrary Knudsen
numbers.Comment: 12 pages, 5 figure
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