  Despite its importance, the understanding of ionic cloud distribution close
to a charged macroion under physiological salt conditions has remained very
limited especially for strongly coupled systems with, for instance, multivalent
counterions. Here we present a formalism that predicts both counterion and
coion distributions in the vicinity of a charged macroion for an arbitrary
amount of added salt and in both limits of mean field and strong coupling. The
distribution functions are calculated explicitly for ions next to an infinite
planar charged wall. We present a schematic phase diagram identifying different
physical regimes in terms of electrostatic coupling parameter and bulk salt
concentration.
