Non-equilibrium relaxation dynamics in two and three dimensional random-field XY model
Abstract Book of the XXIII IUPAP International Conference on Statistical Physics, Genova, Italy, (9-13 July 2007)Abstract
Glassy dynamics in random field systems
is an important open problem in studies of disordered systems.
We study numerically relaxation dynamics
of two and three dimensional random-field XY model
from ordered initial condition by solving Langevin equation.
Roughness of the system develops with time
by both thermal noise and quenched randomness
up to larger wavelengths as the time increases.
We analyzed the structure factor in detail
and found compact scaling laws
describing three distinct time regimes
and crossover between them.
We found the short time regime corresponding to length scales
smaller than the Larkin length $L_c$
is well described by the Larkin model
which predicts a power law growth of the domain size $L(t)$.
The longer time behavior corresponding to length scales
larger than $L_c$ exhibits a random manifold regime
with slower growth of $L(t)$.
The growth of $L(t)$ and thus the roughness is terminated eventually
at some equilibrium correlation length $\xi$
when the random field is sufficiently strong.