Comparative merits of the memory function and dynamic local field correction of the classical one-component plasma

TL;DR

This study compares the effectiveness of the memory function and local field correction models in describing the dynamical properties of the classical one-component plasma, using extensive molecular dynamics simulations.

Contribution

First-time computation of the dynamic local field correction for the OCP and assessment of existing models against MD data.

Findings

DSF well modeled by a memory function approach

LFC poorly described by current models

MD simulations cover a wide fluid regime

Abstract

The complementarity of the liquid and plasma descriptions of the classical one-component plasma (OCP) is explored by studying wavevector and frequency dependent dynamical quantities: the dynamical structure factor (DSF), and the dynamic local field correction (LFC). Accurate Molecular Dynamics (MD) simulations are used to validate/test models of the DSF and LFC. Our simulations, which span the entire fluid regime ($\Gamma = 0.1 - 175$), show that the DSF is very well represented by a simple and well known memory function model of generalized hydrodynamics. On the other hand, the LFC, which we have computed using MD for the first time, is not well described by existing models.