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

Abstract

The numerical modeling of plasmon behavior is crucial for an accurate interpretation of inelastic scattering diagnostics in many experiments. We highlight the utility of linear-response timedependent density functional theory (LR-TDDFT) as an appropriate first-principles framework for a consistent modeling of plasmon properties. We provide a comprehensive analysis of plasmons from ambient throughout warm dense conditions and assess typical properties such as the dynamical structure factor, the plasmon dispersion, and the plasmon width. We compare them with experimental measurements in aluminum accessible via x-ray Thomson scattering and with other dielectric models such as the Lindhard model, the Mermin approach based on parametrized collision frequencies, and the dielectric function obtained using static local field corrections of the uniform electron gas parametrized from path integral Monte Carlo simulations both at the ground state and at finite temperature. We conclude with the remark that the common practice of extracting and employing plasmon dispersion relations and widths is an insufficient procedure to capture the complicated physics contained in the dynamic structure factor in its full breadth.

Analytical representation of the Local Field Correction of the Uniform Electron Gas within the Effective Static Approximation

“…Due to its definition as a frequency-averaged LFC, the ESA is particularly suited for the construction of advanced XC-functionals for DFT simulations based on the adiabatic connection and the fluctuation dissipation theorem [80][81][82][83]. This is a highly desirable project, as the predictive capability of DFT for WDM calculations is still limited [119].…”

“…The bottom panel corresponds to r s = 2, which is relevant e.g. for the investigation of aluminum [42,119].…”

Nonlinear density response from imaginary-time correlation functions: Ab initio path integral Monte Carlo simulations of the warm dense electron gas

“…Eq. ( 18)] for different wave numbers q in the τ1-τ2-plane for the unpolarized UEG with N = 14 at rs = 2 and θ = 2. contemporary research in the field of warm dense matter and can be probed, for example, in experiments with aluminum [90,91]. Furthermore, we note that we depict F (2) (q, τ 1 , τ 2 ) on the same colour-and z-scale for all panels to allow a direct comparison between the results for the different wave numbers.…”

Overcoming finite-size effects in electronic structure simulations at extreme conditions

“…In warm dense matter research, such states are created in many experiments, e.g. using aluminum [84][85][86][87]. In this case, finitesize effects are again reduced in relative importance, and the first-order correction from Eq.…”