Time-Dependent Density-Functional Theory for the Stopping Power of an Interacting Electron Gas for Slow Ions

TL;DR

This paper develops a density-functional theory-based formula to accurately predict the stopping power of an interacting electron gas for slow ions, highlighting the importance of electron correlation effects for intermediate charges.

Contribution

It introduces a rigorous low-velocity stopping power formula within time-dependent density-functional theory that accounts for electron interactions and correlation effects.

Findings

Correlation effects significantly increase stopping power for intermediate ions.

The theory aligns well with experimental data.

Noninteracting electron approximation is recovered without correlation effects.

Abstract

Based on the time-dependent density-functional theory, we have derived a rigorous formula for the stopping power of an {\it interacting} electron gas for ions in the limit of low projectile velocities. If dynamical correlation between electrons is not taken into account, this formula recovers the corresponding stopping power of {\it noninteracting} electrons in an effective Kohn-Sham potential. The correlation effect, specifically the excitonic one in electron-hole pair excitations, however, is found to considerably enhance the stopping power for intermediately charged ions, bringing our theory into good agreement with experiment.