Brownian pump induced by the phase difference between the potential and the entropic barrier
Laboratory of Quantum Engineering and Quantum
Materials, School of Physics and Telecommunication Engineering, South China Normal
Received in final form: 10 October 2013
Published online: 20 November 2013
Transport of Brownian particles in a finite channel is investigated in the presence of a symmetric potential and an unbiased external force. It is found that the phase difference between the potential (energetic barriers) and the entropic barrier can break the symmetry of the system and control the transport of Brownian particles. Especially, the particles can be pumped through the channel from a reservoir at low concentration to one at the same or higher concentration. There exist optimized values of the parameters (the temperature and the amplitude of the external force) at which the pumping capacity takes its maximum value. The pumping capacity decreases with increasing the radius at the bottleneck of the channel.
Key words: Statistical and Nonlinear Physics
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2013