Fluctuating noise drives Brownian transport

TL;DR

This paper investigates how fluctuating environmental noise influences Brownian ratchet transport, revealing optimal noise correlation times that enhance current and relate to biological gene expression variability.

Contribution

It demonstrates the impact of stochastic intensity noise on Brownian transport, combining analytical and simulation methods to identify optimal noise correlation times.

Findings

Maximum current occurs at intermediate noise correlation times.

Optimal noise correlation matches biological gene expression noise.

Environmental noise significantly affects molecular transport mechanisms.

Abstract

The transport properties of Brownian ratchet was studied in the presence of stochastic intensity noise (SIN) in both overdamped and underdamped regimes. In the overdamped case, analytical solution using the matrix continued fraction method revealed the existence of a maximum current when the noise intensity fluctuates on intermediate time scale regions. Similar effects were observed for the underdamped case by Monte Carlo simulations. The optimal time-correlation for the Brownian transport coincided with the experimentally observed time-correlation of the extrinsic noise in Esherichia coli gene expression and implied the importance of environmental noise for molecular mechanisms.