Temporally Asymmetric Fluctuations are Sufficient for the Operation of a Correlation Ratchet

TL;DR

This paper demonstrates that temporally asymmetric fluctuations alone can drive work in a ratchet system without the need for spatial asymmetry, expanding understanding of nonequilibrium biological processes.

Contribution

It shows that broken spatial symmetry is not necessary for a ratchet to operate; temporally asymmetric fluctuations are sufficient.

Findings

Temporally asymmetric fluctuations can generate work in symmetric ratchets.

Spatial symmetry breaking is not required for ratchet operation.

Temporal asymmetry is common in biological nonequilibrium systems.

Abstract

It has been shown that the combination of a broken spatial symmetry in the potential (or ratchet potential) and time correlations in the driving are crucial, and enough to allow transformation of the fluctuations into work. The required broken spatial symmetry implies a specific molecular arrangement of the proteins involved. Here we show that a broken spatial symmetry is not required, and that temporally asymmetric fluctuations (with mean zero) can be used to do work, even when the ratchet potential is completely symmetric. Temporal asymmetry, defined as a lack of invariance of the statistical properties under the operation to temporal inversion, is a generic property of nonequilibrium fluctuation, and should therefore be expected to be quite common in biological systems.