A. Rosso et W. Krauth, Origin of the roughness exponent in elastic strings at the depinning threshold - art. no. 187002, PHYS REV L, 8718(18), 2001, pp. 7002
Within a recently developed framework of dynamical Monte Carlo algorithms,
we compute the roughness exponent zeta of driven elastic strings at the dep
inning threshold in 1 + 1 dimensions for different functional forms. of the
(short-range) elastic energy. A purely harmonic elastic energy leads to an
unphysical value for. We include supplementary terms in the elastic energy
of at least quartic order in the local extension. We then find a roughness
exponent of zeta similar or equal to 0.63, which coincides with the one ob
tained for different cellular automaton models of directed percolation depi
nning. We discuss the implications of our analysis for higher-dimensional e
lastic manifolds in disordered media.