9 research outputs found
Ageing, dynamical scaling and its extensions in many-particle systems without detailed balance
Recent studies on the phenomenology of ageing in certain many-particle
systems which are at a critical point of their non-equilibrium steady-states,
are reviewed. Examples include the contact process, the parity-conserving
branching-annihilating random walk, two exactly solvable particle-reaction
models and kinetic growth models. While the generic scaling descriptions known
from magnetic system can be taken over, some of the scaling relations between
the ageing exponents are no longer valid. In particular, there is no obvious
generalization of the universal limit fluctuation-dissipation ratio. The form
of the scaling function of the two-time response function is compared with the
prediction of the theory of local scale-invariance.Comment: Latex2e with IOP macros, 32 pages; extended discussion on contact
process and new section on kinetic growth processe
Ageing in disordered magnets and local scale-invariance
The ageing of the bond-disordered two-dimensional Ising model quenched to
below its critical point is studied through the two-time autocorrelator and
thermoremanent magnetization (TRM). The corresponding ageing exponents are
determined. The form of the scaling function of the TRM is well described by
the theory of local scale-invariance.Comment: Latex2e, with epl macros, 7 pages, final for
Aging processes in reversible reaction-diffusion systems
Reversible reaction-diffusion systems display anomalous dynamics
characterized by a power-law relaxation toward stationarity. In this paper we
study in the aging regime the nonequilibrium dynamical properties of some model
systems with reversible reactions. Starting from the exact Langevin equations
describing these models, we derive expressions for two-time correlation and
autoresponse functions and obtain a simple aging behavior for these quantities.
The autoresponse function is thereby found to depend on the specific nature of
the chosen perturbation of the system.Comment: 12 pages, accepted for publication in Phys. Rev.
Nonequilibrium relaxation and scaling properties of the two-dimensional Coulomb glass in the aging regime
We employ Monte Carlo simulations to investigate the two-time density
autocorrelation function for the two-dimensional Coulomb glass. We find that
the nonequilibrium relaxation properties of this highly correlated disordered
system can be described by a full aging scaling ansatz. The scaling exponents
are non-universal, and depend on temperature and charge density.Comment: 6 pages, 3 figures included; revised version: corrected exponents,
and some additional explanations and references added; to appear in EP
Aging processes in reversible reaction-diffusion systems: Monte Carlo simulations
Reaction-diffusion systems with reversible reactions generically display
power-law relaxation towards chemical equilibrium. In this work we investigate
through numerical simulations aging processes that characterize the
non-equilibrium relaxation. Studying a model which excludes multiple occupancy
of a site, we find that the scaling behavior of the two-time correlation and
response functions are similar to that discovered previously in an exactly
solvable version with no restrictions on the occupation numbers. Especially, we
find that the scaling of the response depends on whether the perturbation
conserves a certain quantity or not. Our results point to a high degree of
universality in relaxation processes taking place in diffusion-limited systems
with reversible reactions.Comment: 12 pages, 4 figures included, accepted for publication in JSTA
Out-of-equilibrium properties of the semi-infinite kinetic spherical model
We study the ageing properties of the semi-infinite kinetic spherical model
at the critical point and in the ordered low-temperature phase, both for
Dirichlet and Neumann boundary conditions. The surface fluctuation-dissipation
ratio and the scaling functions of two-time surface correlation and response
functions are determined explicitly in the dynamical scaling regime. In the
low-temperature phase our results show that for the case of Dirichlet boundary
conditions the value of the non-equilibrium surface exponent differs from
the usual bulk value of systems undergoing phase ordering.Comment: 22 pages, 4 figures included, submitted to J. Phys.
Scaling and super-universality in the coarsening dynamics of the 3d random field Ising model
We study the coarsening dynamics of the three-dimensional random field Ising
model using Monte Carlo numerical simulations. We test the dynamic scaling and
super-scaling properties of global and local two-time observables. We treat in
parallel the three-dimensional Edward-Anderson spin-glass and we recall results
on Lennard-Jones mixtures and colloidal suspensions to highlight the common and
different out of equilibrium properties of these glassy systems.Comment: 18 pages, 21 figure