Dynamic exchange-correlation effects in the strongly coupled electron liquid

TL;DR

This paper provides quasi-exact ab initio PIMC results for the dynamic local field correction in the strongly coupled finite temperature electron gas, revealing the importance of dynamic exchange-correlation effects and challenging the static approximation.

Contribution

First quasi-exact ab initio PIMC results for the dynamic local field correction in the strongly coupled electron gas, enabling better understanding of exchange-correlation effects.

Findings

Dynamic effects significantly impact the static structure factor.

Static approximation neglects important frequency dependence.

Results suggest potential for analytical parametrization of the local field correction.

Abstract

We present the first quasi-exact \textit{ab initio} path integral Monte Carlo (PIMC) results for the dynamic local field correction $\widetilde{G}(\mathbf{q},z_l;r_s,\Theta)$ in the imaginary Matsubara frequency domain, focusing on the strongly coupled finite temperature uniform electron gas. These allow us to investigate the impact of dynamic exchange--correlation effects onto the static structure factor. Our results provide a straightforward explanation for previously reported spurious effects in the so-called \textit{static approximation} [Dornheim \textit{et al.}, \textit{Phys.~Rev.~Lett.}~\textbf{125}, 235001 (2020)], where the frequency-dependence of the local field correction is neglected. Our findings hint at the intriguing possibility of constructing an analytical four-parameter representation of $\widetilde{G}(\mathbf{q},z_l;r_s,\Theta)$ valid for a substantial part of the phase diagram, which would constitute key input for thermal density functional theory simulations.