Strong-coupling electrostatics for two dissimilar charged walls

We study the effective interaction between two parallel charged plates, modelling macromolecules, or colloids, in the strongly coupled Coulomb regime. Neutralizing mobile ions are point-like and confined in the inter-plate slab. A cumulant technique provides exact expansions, beyond the leading strong-coupling order, that are in remarkable agreement with simulation data for both the ionic profile and the inter-plate pressure. The present approach amounts to a summation over relevant excitations around the Wigner Crystal ground state formed at infinite coupling; It thereby differs from previous virial-like strong-coupling theories and generalizes a recent work by the authors to asymmetric plates.