Driving particle current through narrow channels using classical pump

TL;DR

This paper investigates a classical particle pump in a symmetric exclusion process with time-varying hopping rates, demonstrating how phase differences induce a directed current, analyzed through simulations and a new perturbative approach.

Contribution

It introduces a novel perturbative method to derive the DC current in a symmetric exclusion process with time-dependent hopping rates, highlighting the phase-controlled particle transport mechanism.

Findings

Phase difference controls current direction

Derived an analytical expression for DC current

Simulations confirm theoretical predictions

Abstract

We study a symmetric exclusion process in which the hopping rates at two chosen adjacent sites vary periodically in time and have a relative phase difference. This mimics a colloidal suspension subjected to external space and time dependent modulation of the diffusion constant. The two special sites act as a classical pump by generating an oscillatory current with a nonzero ${\cal DC}$ value whose direction depends on the applied phase difference. We analyze various features in this model through simulations and obtain an expression for the $\cal{DC}$ current via a novel perturbative treatment.