Nonlinear response of electrons to a positive ion

TL;DR

This paper investigates the nonlinear behavior of electrons around a positive ion using semiclassical models and MD simulations, revealing how charge number influences electric field correlations and transport properties.

Contribution

It introduces a combined semiclassical and MD simulation approach to analyze nonlinear electron responses to positive ions, highlighting charge-dependent correlation dynamics.

Findings

Correlation time decreases with increasing charge number

Anticorrelation emerges at larger charge numbers

Transport coefficients are influenced by competing correlation effects

Abstract

Electric field dynamics at a positive ion imbedded in an electron gas is considered using a semiclassical description. The dependence of the field autocorrelation function on charge number is studied for strong ion-electron coupling via MD simulation. The qualitative features for larger charge numbers are a decreasing correlation time followed by an increasing anticorrelation. Stopping power and related transport coefficients determined by the time integral of this correlation function result from the competing effects of increasing initial correlations and decreasing dynamical correlations. An interpretation of the MD results is obtained from an effective single particle model showing good agreement with the simulation results.