Efficiency and current reversals in spatially inhomogeneous ratchets

TL;DR

This paper investigates how spatial inhomogeneity and noise influence the efficiency and direction of current in ratchet systems, revealing maximum efficiency at specific temperatures and current reversals with noise variations.

Contribution

It introduces analysis of efficiency maxima and current reversals in inhomogeneous and asymmetric ratchet systems, highlighting the effects of spatially varying friction and noise.

Findings

Efficiency peaks at certain temperatures in inhomogeneous systems.

Current direction can reverse as noise strength varies.

Maximum efficiency does not coincide with maximum current.

Abstract

Efficiency of generation of net unidirectional current in an adiabatically driven symmetric periodic potential system is studied. The efficiency shows a maximum, in the case of an inhomogeneous system with spatially varying periodic friction coefficient, as a function of temperature. The ratchet is not most efficient when it gives maximum current. The direction of current may also be reversed as a function of noise strength when, instead, an asymmetric periodic potential is considered.