Universal interface width distributions at the depinning threshold
Alberto Rosso1, Werner Krauth1,
Pierre Le Doussal2, Jean Vannimenus1, Kay
Jörg Wiese3
1CNRS-Laboratoire de Physique Statistique de
l'Ecole Normale Supérieure,
24 rue Lhomond, 75005 Paris, France
2CNRS-Laboratoire de Physique Théorique de
l'Ecole Normale Supérieure,
24 rue Lhomond, 75005 Paris, France
3KITP, University of California at Santa Barbara, Santa
Barbara, CA 93106-4030, USA
Abstract
We compute the probability distribution of
the interface width at the depinning threshold, using recent powerful
algorithms. It confirms the universality classes found previously. In
all cases, the distribution is surprisingly well approximated by a
generalized Gaussian theory of independant modes which decay with a
characteristic propagator
G(q)=1/qd+2ζ; ζ, the
roughness exponent, is computed independently. A functional
renormalization analysis explains this result and allows to compute
the small deviations, i.e. a universal kurtosis ratio, in agreement
with numerics. We stress the importance of the Gaussian theory to
interpret numerical data and experiments.
cond-mat/0301464 [pdf]
Phys. Rev. E 68 (2003) 036128 [pdf]
Copyright (C) by Kay Wiese. Last edited March 17, 2008.