Ionization potential depression and Fermi barrier in warm dense matter--a first--principles approach

TL;DR

This paper discusses a first-principles quantum Monte Carlo approach to accurately predict ionization potential depression in warm dense matter, emphasizing the role of the Fermi barrier.

Contribution

It introduces a detailed first-principles method for calculating IPD, focusing on the Fermi barrier's impact in dense plasmas with higher nuclear charge.

Findings

Demonstrated the approach for hydrogen with quantum Monte Carlo simulations.

Highlighted the significance of the Fermi barrier in IPD calculations.

Provided insights into the variability of existing IPD models.

Abstract

Ionization potential depression (IPD) is of crucial importance to understand and accurately predict the properties of dense partially ionized plasmas. Many models of IPD have been developed that, however, exhibit largely varying results. Recently, a novel approach was proposed that is based on first-principles quantum Monte Carlo simulations and that was demonstrated for hydrogen [Bonitz \textit{et al.}, Phys. Plasmas (2024)]. Here this concept is discussed in more detail. Particular attention is devoted to the Fermi barrier that electrons have to overcome upon ionization and which significantly contributes to IPD when the nuclear charge increases.