Spatial Charge Profile Anomalies and Phase Transitions in Modified One-Component Plasma Models

This paper discusses the appearance of discontinuities in the equilibrium spatial charge profiles in inhomogeneous Coulomb systems in a wide range of thermoelectrostatic problems. Such discontinuities are considered as a kind of microlevel manifestation of phase transitions and internal macrolevel effects of nonideality in the local equation of state (EOS), which is used to describe a nonideal electronic or ionic subsystem within the local density approximation (pseudofluid, jelly, etc.). Particular attention is paid to the effects of nonideality in inhomogeneous ionic subsystems, such as the profile of microions in a screening cloud around macroions in a complex (dusty, colloidal, etc.) plasma, the equilibrium charge profile in ion traps, or in the vicinity of a charged wall. In addition, a multiphase EOS for a simplified ionic model of classical charged hard spheres on a uniformly compressible electrostatic compensating background is constructed and several illustrative examples of the discussed discontinuous ion profiles are calculated.