Diffusion in periodic, correlated random forcing landscapes

D. Dean,Shamik Gupta,G. Oshanin,A. Rosso,G. Schehr

Published 2014 in Journal of Physics A: Mathematical and Theoretical

ABSTRACT

We study the dynamics of a Brownian particle in a strongly correlated quenched random potential defined as a periodically–extended (with period L) finite trajectory of a fractional Brownian motion with arbitrary Hurst exponent H ∈ ( 0 , 1 ) ?> . While the periodicity ensures that the ultimate long–time behavior is diffusive, the generalized Sinai potential considered here leads to a strong logarithmic confinement of particle trajectories at intermediate times. These two competing trends lead to dynamical frustration and result in a rich statistical behavior of the diffusion coefficient D L : although one has the typical value D L typ ∼ exp ( − &bgr; L H ) ?> , we show via an exact analytical approach that the positive moments ( k > 0 ?> ) scale like ⟨ D L k ⟩ ∼ exp [ − c ′ ( k &bgr; L H ) 1 / ( 1 + H ) ] ?> , and the negative ones as ⟨ D L − k ⟩ ∼ exp ( a ′ ( k &bgr; L H ) 2 ) ?> , c ′ ?> and a ′ ?> being numerical constants and β the inverse temperature. These results demonstrate that D L is strongly non-self-averaging. We further show that the probability distribution of D L has a log–normal left tail and a highly singular, one–sided log–stable right tail reminiscent of a Lifshitz singularity.

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CONCEPTS

REFERENCES

Showing 1-52 of 52 references · Page 1 of 1

CITED BY

Showing 1-35 of 35 citing papers · Page 1 of 1