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.
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
PUBLICATION RECORD
- Publication year
2014
- Venue
Journal of Physics A: Mathematical and Theoretical
- Publication date
2014-06-10
- Fields of study
Mathematics, Physics
- Identifiers
- External record
- Source metadata
Semantic Scholar
CITATION MAP
EXTRACTION MAP
CLAIMS
CONCEPTS
- brownian particle
A diffusing particle whose motion is studied in the random potential landscape.
Aliases: particle
- diffusion coefficient d_l
The effective long-time diffusion coefficient associated with a particle moving in a period-L random landscape.
Aliases: D_L, DL
- fractional brownian motion
A Gaussian stochastic process used here as the source trajectory for the random potential, characterized by a Hurst exponent.
Aliases: FBM
- hurst exponent
The parameter H in (0,1) that controls the roughness and correlation structure of the fractional Brownian motion.
Aliases: H
- log-normal left tail
The low-value side of the diffusion-coefficient distribution, described here by a log-normal form.
Aliases: left tail
- one-sided log-stable right tail
The high-value side of the diffusion-coefficient distribution, described here by a singular one-sided log-stable form.
Aliases: right tail
- periodically extended quenched random potential
A frozen random landscape built by repeating a finite fractional-Brownian trajectory with spatial period L.
Aliases: periodic quenched random potential, periodically extended random forcing landscape
REFERENCES
Showing 1-52 of 52 references · Page 1 of 1
CITED BY
Showing 1-35 of 35 citing papers · Page 1 of 1