Long-range fluctuation-induced forces in driven electrolytes

TL;DR

This paper investigates how nonequilibrium conditions in driven electrolytes lead to long-range correlations and Casimir-like forces, which can be tuned by external electric fields to control interactions between neutral structures.

Contribution

It demonstrates the existence of long-range fluctuation-induced forces in electrolytes under external driving, highlighting their tunability and deviation from equilibrium behavior.

Findings

Long-range correlations persist despite Debye screening.

External electric fields control the magnitude and sign of the forces.

Forces can be attractive or repulsive under similar boundary conditions.

Abstract

We study the stochastic dynamics of an electrolyte driven by a uniform external electric field and show that it exhibits generic scale invariance despite the presence of Debye screening. The resulting long-range correlations give rise to a Casimir-like fluctuation-induced force between neutral boundaries that confine the ions; this force is controlled by the external electric field, and it can be both attractive and repulsive with similar boundary conditions, unlike other long-range fluctuation-induced forces. This work highlights the importance of nonequilibrium correlations in electrolytes and shows how they can be used to tune interactions between uncharged biological or synthetic structures at large separations.