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)
- Fluctuation phenomena, random processes, noise, and Brownian motion.
PACS. 02.50Ey - Stochastic processes.
PACS. 05.60 - 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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