Vasyl Kharchenko, Igor Goychuk
We study subdiffusive ratchet transport in periodically and randomly flashing
potentials. Central Brownian particle is elastically coupled to surrounding
auxiliary Brownian quasi-particles which account for the influence of
viscoelastic environment. Similar to standard dynamical modeling of Brownian
motion, the external force influences only the motion of central particle not
affecting directly the environmental degrees of freedom (see video). Just a
handful of auxiliary Brownian particles suffice to model subdiffusion over many
temporal decades. Time-modulation of the potential violates the symmetry of
thermal detailed balance and induces anomalous subdiffusive current which
exhibits a remarkable quality at low temperatures, as well as a number of other
surprising features such as saturation at low temperatures, and multiple
inversions of the transport direction upon a change of the driving frequency in
nonadiabatic regime. Our study generalizes classical Brownian motors towards
operating in sticky viscoelastic environments like cytosol of biological cells
or dense polymer solutions.
View original:
http://arxiv.org/abs/1201.5287
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