1,007 research outputs found
Spin Conductance in one-dimensional Spin-Phonon systems
We present results for the spin conductance of the one dimensional spin-1/2
Heisenberg and XY model coupled to phonons. We apply an approach based on the
Stochastic Series Expansion (Quantum Monte Carlo) method to evaluate the
conductance for a variety of phonon dispersions and values of spin-phonon
coupling. From our numerical simulations and analytical arguments, we derive
several scaling laws for the conductance.Comment: 7 pages, 9 figure
Comparing the behavior of orbits in different 3D dynamical models for elliptical galaxies
We study the behavior of orbits in two different galactic dynamical models,
describing the motion in the central parts of a triaxial elliptical galaxy with
a dense nucleus. Numerical experiments show that both models display regular
motion together with extended chaotic regions. A detailed investigation of the
properties of motion is made for the 2D and 3D Hamiltonian systems, using a
number of different dynamical parameters, such as the Poincare surface of
section, the maximal Lyapunov Characteristic Exponent, the S(c) spectrum, the
S(w) spectrum and the P(f) indicator. The numerical calculations suggest that
the properties of motion in both potentials are very similar. Our results show
that one may use different kinds of gravitational potentials in order to
describe the motion in triaxial galaxies while obtaining quantitatively similar
results.Comment: Published in Research in Astronomy and Astrophysics journa
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