First-principles modeling of plasmons in aluminum under ambient and extreme conditions

TL;DR

This paper uses first-principles linear-response TDDFT to model and analyze plasmon behavior in aluminum across various conditions, revealing discrepancies between theory and experiment and highlighting the complexity of plasmon physics.

Contribution

It demonstrates the application of LR-TDDFT for comprehensive plasmon analysis in aluminum under different conditions, comparing results with experiments and other models.

Findings

Discrepancies between experimental and theoretical plasmon dispersion and lifetime.

Common methods for extracting plasmon dispersion are insufficient to capture full physics.

Dynamic structure factor analysis reveals complex plasmon behavior.

Abstract

The theoretical understanding of plasmon behavior is crucial for an accurate interpretation of inelastic scattering diagnostics in many experiments. We highlight the utility of linear-response time-dependent density functional theory (LR-TDDFT) as a first-principles framework for consistently modeling plasmon properties. We provide a comprehensive analysis of plasmons in aluminum from ambient to warm dense matter conditions and assess typical properties such as the dynamical structure factor, the plasmon dispersion, and the plasmon lifetime. We compare our results with scattering measurements and with other TDDFT results as well as models such as the random phase approximation, the Mermin approach, and the dielectric function obtained using static local field corrections of the uniform electron gas parametrized from path integral Monte Carlo simulations. We conclude that results for the plasmon dispersion and lifetime are inconsistent between experiment and theories and that the common practice of extracting and studying plasmon dispersion relations is an insufficient procedure to capture the complicated physics contained in the dynamic structure factor in its full breadth.