Europhys. Lett.
Volume 48, Number 5, December 1999
Page(s) 491 - 497
Section General
Published online 01 September 2002
DOI: 10.1209/epl/i1999-00510-7

Europhys. Lett, 48 (5), pp. 491-497 (1999)

Threshold diffusion in a tilted washboard potential

G. Costantini and F. Marchesoni

Istituto Nazionale di Fisica della Materia, Università di Camerino
I-62032 Camerino (Macerata), Italy

(received 26 May 1999; accepted in final form 30 September 1999)

PACS. 05.40${\rm -a}$ - Fluctuation phenomena, random processes, noise, and Brownian motion.
PACS. 02.50Ey - Stochastic processes.
PACS. 05.60${\rm -k}$ - Transport processes.


We characterize the locked-to-running transition of a Brownian particle in a tilted washboard potential by looking at its transport properties in the vicinity of the transition threshold. At low temperatures the (normal) spatial diffusion of the particle is enhanced as a consequence of the unlocking mechanism; in the overdamped regime an analytic expression is obtained that relates the particle diffusion constant to its mobility; in the underdamped regime an unusually large diffusion constant is revealed through numerical simulation. The latter regime is analyzed in terms of multiple jump statistics.


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