Brownian pump in nonlinear diffusive media

TL;DR

This paper analyzes a Brownian pump operating in nonlinear diffusive media, deriving analytical expressions for current and capacity across diffusion types, revealing significant anomalies and contrasting behaviors at different temperatures.

Contribution

It provides the first analytical expressions for Brownian pump behavior in nonlinear diffusive media, highlighting unique anomalies across diffusion regimes.

Findings

Superdiffusive regime shows opposite current at low temperatures.

Subdiffusive regime can have forbidden or negative current depending on temperature.

Normal diffusion exhibits standard current behavior.

Abstract

A Brownian pump in nonlinear diffusive media is investigated in the presence of an unbiased external force. The pumping system is embedded in a finite region and bounded by two particle reservoirs. In the adiabatic limit, we obtain the analytical expressions of the current and the pumping capacity as a function of temperature for normal diffusion, subdiffusion and superdiffusion. It is found that important anomalies are detected in comparison to the normal diffusion case. The superdiffusive regime, compared with the normal one, exhibits an opposite current for low temperatures. In subdiffusive regime, the current may become forbidden for low temperatures and negative for high temperatures.