Phenomenological plasmon broadening and relation to the dispersion

TL;DR

This paper critically compares methods for including lifetime broadening of collective modes in the electron liquid, focusing on how damping affects dispersion, with quantitative examples for 2D charge and spin-density plasmons.

Contribution

It provides a comparative analysis of pragmatic approaches to incorporate lifetime broadening and examines their impact on plasmon dispersion in two-dimensional systems.

Findings

Deviations due to damping are within experimental resolution.

Impact of damping parameter varies with plasmon type.

Quantitative examples for 2D plasmons are provided.

Abstract

Pragmatic ways of including lifetime broadening of collective modes in the electron liquid are critically compared. Special focus lies on the impact of the damping parameter onto the dispersion. It is quantitatively exemplified for the two-dimensional case, for both, the charge (`sheet'-)plasmon and the spin-density plasmon. The predicted deviations fall within the resolution limits of advanced techniques.