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Evaluating Government's Policies on Promoting Smart Metering in Retail Electricity Markets via Agent Based Simulation
The Isotope Effect in Superconductors
We review some aspects of the isotope effect (IE) in superconductors. Our
focus is on the influence of factors not related to the pairing mechanism.
After summarizing the main results obtained for conventional superconductors,
we review the effect of magnetic impurities, the proximity effect and
non-adiabaticity on the value of the isotope coefficient (IC). We discuss the
isotope effect of and of the penetration depth . The theory is
applied to conventional and high- superconductors. Experimental results
obtained for YBaCuO related materials (Zn and
Pr-substituted as well as oxygen-depleted systems) and for
LaSrCuO are discussed.Comment: 31 pages, 10 figures. Review article to appear in "Pair Correlation
in Many Fermions Systems", Plenum Press 199
Motion of domain walls and the dynamics of kinks in the magnetic Peierls potential
We study the dynamics of magnetic domain walls in the Peierls potential due
to the discreteness of the crystal lattice. The propagation of a narrow domain
wall (comparable to the lattice parameter) under the effect of a magnetic field
proceeds through the formation of kinks in its profile. We predict that,
despite the discreteness of the system, such kinks can behave like sine-Gordon
solitons in thin films of materials such as yttrium iron garnets, and we derive
general conditions for other materials. In our simulations we also observe
long-lived breathers. We provide analytical expressions for the effective mass
and limiting velocity of the kink in excellent agreement with our numerical
results.Comment: 12 pages, 9 figures (incl. supp. mat.
Helical damping and anomalous critical non-Hermitian skin effect
Non-Hermitian skin effect and critical skin effect are unique features of
non-Hermitian systems. In this Letter, we study an open system with its
dynamics of single-particle correlation function effectively dominated by a
non-Hermitian damping matrix, which exhibits skin effect, and
uncover the existence of a novel phenomenon of helical damping. When adding
perturbations that break anomalous time reversal symmetry to the system, the
critical skin effect occurs, which causes the disappearance of the helical
damping in the thermodynamic limit although it can exist in small size systems.
We also demonstrate the existence of anomalous critical skin effect when we
couple two identical systems with skin effect. With the help of
non-Bloch band theory, we unveil that the change of generalized Brillouin zone
equation is the necessary condition of critical skin effect.Comment: 7+5 pages, 4+5 figure
Influence of the nonlinearity parameter on the solar-wind sub-ion magnetic energy spectrum: FLR-Landau fluid simulations
The cascade of kinetic Alfv\'en waves (KAWs) at the sub-ion scales in the
solar wind is numerically simulated using a fluid approach that retains ion and
electron Landau damping, together with ion finite Larmor radius corrections.
Assuming initially equal and isotropic ion and electron temperatures, and an
ion beta equal to unity, different simulations are performed by varying the
propagation direction and the amplitude of KAWs that are randomly driven at a
transverse scale of about one fifth of the proton gyroradius in order to
maintain a prescribed level of turbulent fluctuations. The resulting turbulent
regimes are characterized by the nonlinearity parameter, defined as the ratio
of the characteristic times of Alfv\'en wave propagation and of the transverse
nonlinear dynamics. The corresponding transverse magnetic energy spectra
display power laws with exponents spanning a range of values consistent with
spacecraft observations. The meandering of the magnetic field lines together
with the ion temperature homogenization along these lines are shown to be
related to the strength of the turbulence, measured by the nonlinearity
parameter. The results are interpreted in terms of a recently proposed
phenomenological model where the homogenization process along field lines
induced by Landau damping plays a central role
Rheology in dense assemblies of spherocylinders: frictional vs. frictionless
Using molecular dynamics simulations, we study the steady shear flow of dense
assemblies of anisotropic spherocylindrical particles of varying aspect ratios.
Comparing frictionless and frictional particles we discuss the specific role of
frictional inter-particle forces for the rheological properties of the system.
In the frictional system we evidence a shear-thickening regime, similar to that
for spherical particles. Furthermore, friction suppresses alignment of the
spherocylinders along the flow direction. Finally, the jamming density in
frictional systems is rather insensitive to variations in aspect-ratio, quite
contrary to what is known from frictionless systems
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