Home
| VOLUME 105 (2017) | ISSUE 8 | PAGE 521 |
|---|
|
A theory of slightly fluctuating ratchets
V. M. Rozenbauma,b,c, I. V. Shapochkinaa,b,d, S. H. Lina,b, L. I. Trakhtenberge,f
aInstitute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan bDepartment of Applied Chemistry, National Chiao Tung University, 1001 Hsinchu, Taiwan cChuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, 03164 Kiev, Ukraine dDepartment of Physics, Belarusian State University, 220050 Minsk, Belarus eSemenov Institute of Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Russia fState Scientific Center, Russian Federation, Karpov Institute of Physical Chemistry, 105064 Moscow, Russia
Abstract
We consider a Brownian particle moving in a slightly fluctuating potential. Using the perturbation theory on small potential fluctuations, we derive a general analytical expression for the average particle velocity valid for both flashing and rocking ratchets with arbitrary, stochastic or deterministic, time dependence of potential energy fluctuations. The result is determined by the Green's function of diffusion in the time-independent part of the potential and by the features of correlations in the fluctuating part of the potential. The generality of the result allows describing complex ratchet systems with competing characteristic times; these systems are exemplified by the model of a Brownian photomotor with relaxation processes of finite duration. |