  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.
