Entropic transport of interacting Brownian particles in a channel with reflecting boundaries

The entropic transport of overdamped biased Brownian particles in a symmetric channel is investigated numerically considering both the no-flow and the reflection boundary conditions at the channel boundaries. The constrained dynamics yields a scaling parameter f, which is a ratio of the work done to the particles to available thermal energy. The distinct transport features are observed with reflection boundary conditions, for example, the nonlinear mobility exhibits a nonmonotonic behavior as a function of the scaling parameter f, and the effective diffusion coefficient exhibits a rapidly increasing behavior at higher f, which are not observed with no-flow boundary conditions. We show that the transport properties can be significantly influenced by the nature of reflection, i.e., elastic or inelastic. In doing so, we identify that both the nonlinear mobility and the effective diffusion coefficient can be enhanced with inelastic reflection boundary conditions. In addition, by including the short range interaction force between the Brownian particles, the mobility decreases, and the effective diffusion coefficient increases for the optimal values of f.