Electronic density response of warm dense hydrogen on the nanoscale

TL;DR

This paper presents new ab initio PIMC simulations revealing the electronic density response of warm dense hydrogen at the nanoscale, providing insights into electron localization and benchmarking data for theoretical models.

Contribution

The study offers novel PIMC results on electronic properties of warm dense hydrogen, highlighting complex localization effects and limitations of local uniform electron gas models.

Findings

Qualitative agreement with local uniform electron gas model

Identification of trends not captured by simplified models

Results valuable for benchmarking density functional theory

Abstract

The properties of hydrogen at warm dense matter (WDM) conditions are of high importance for the understanding of astrophysical objects and technological applications such as inertial confinement fusion. In this work, we present extensive new \emph{ab initio} path integral Monte Carlo (PIMC) results for the electronic properties in the Coulomb potential of a fixed ionic configuration. This gives us new insights into the complex interplay between the electronic localization around the protons with their density response to an external harmonic perturbation. We find qualitative agreement between our simulation data and a heuristic model based on the assumption of a local uniform electron gas model, but important trends are not captured by this simplification. In addition to being interesting in their own right, we are convinced that our results will be of high value for future projects, such as the rigorous benchmarking of approximate theories for the simulation of WDM, most notably density functional theory.