  Understanding how electrolyte solutions behave out of thermal equilibrium is
a long-standing endeavor in many areas of chemistry and biology. Although
mean-field theories are widely used to model the dynamics of electrolytes, it
is also important to characterize the effects of fluctuations in these systems.
In a previous work, we showed that the dynamics of the ions in a strong
electrolyte that is driven by an external electric field can generate
long-ranged correlations manifestly different from the equilibrium screened
correlations; in the nonequilibrium steady state, these correlations give rise
to a novel long-range fluctuation-induced force (FIF). Here, we extend these
results by considering the dynamics of the strong electrolyte after it is
quenched from thermal equilibrium upon the application of a constant electric
field. We show that the asymptotic long-distance limit of both charge and
density correlations is generally diffusive in time. These correlations give
rise to long-ranged FIFs acting on the neutral confining plates with long-time
regimes that are governed by power-law temporal decays toward the steady-state
value of the force amplitude. These findings show that nonequilibrium
fluctuations have nontrivial implications on the dynamics of objects immersed
in a driven electrolyte, and they could be useful for exploring new ways of
controlling long-distance forces in charged solutions.
