title: One-dimensional counterion gas between charged surfaces: exact results compared with weak- and strong-coupling analyses.
abstract: We evaluate exactly the statistical integral for an inhomogeneous one-dimensional (1D) counterion-only Coulomb gas between two charged boundaries and from this compute the effective interaction, or disjoining pressure, between the bounding surfaces. Our exact results are compared to the limiting cases of weak and strong couplings which are the same for 1D and three-dimensional (3D) systems. For systems with a large number of counterions it is found that the weak-coupling (mean-field) approximation for the disjoining pressure works perfectly and that fluctuations around the mean-field in 1D are much smaller than in 3D. In the case of few counterions it works less well and strong-coupling approximation performs much better as it takes into account properly the discreteness of the counterion charges.
authors.affiliation: Laboratoire de Physique Théorique (IRSAMC), Université de Toulouse, UPS, Toulouse, France. dean@irsamc.ups-tlse.fr
authors.forename: David S
authors.initials: DS
authors.lastname: Dean
authors.forename: Ron R
authors.initials: RR
authors.lastname: Horgan
authors.forename: Ali
authors.initials: A
authors.lastname: Naji
authors.forename: Rudolf
authors.initials: R
authors.lastname: Podgornik
mesh_terms: D005740:Gases / Q000737:chemistry*; D007477:Ions; D008956:Models, Chemical; D015233:Models, Statistical; D055672:Static Electricity
chemical_list: D005740:Gases; D007477:Ions