Simulations of strongly coupled charged particle systems: static and dynamical properties of classical bilayers

Abstract

This paper reviews our recent molecular dynamics simulation studies of the static and dynamical behaviour of classical bilayers in their liquid phase. The pair correlation functions obtained in the static calculations make it possible to trace the structural changes of the system as well as to calculate the energy and static structure functions of the bilayer. The dynamical calculations show the existence of two (in-phase and out-of-phase) longitudinal and two (in-phase and out-of-phase) transverse collective modes. We present the full dispersion relations for these modes at different layer separations. At low layer separations the out-of-phase modes are found to possess a finite frequency at wave numbers k → 0, confirming the existence of the long-wavelength energy gap in the bilayer system predicted by the quasi-localized charge approximation. It is only at higher layer separations that the dominant portion of the longitudinal out-of-phase mode is well approximated by the acoustic behaviour, resulting from the random phase approximation theory.