Resistivity in warm dense plasmas beyond the average-atom model

TL;DR

This paper introduces a superconfiguration-based approach to calculate electrical resistivity in warm dense plasmas, going beyond the average-atom model by accounting for all electronic configurations with a self-consistent density-functional framework.

Contribution

It develops a novel superconfiguration formalism for resistivity calculations, incorporating detailed electronic configurations and relativistic effects, improving accuracy over traditional average-atom models.

Findings

Superconfiguration model matches experimental resistivity data.

Method captures a wide range of electronic configurations.

Relativistic corrections improve phase shift calculations.

Abstract

The exploration of atomic properties of strongly coupled partially degenerate plasmas, also referred to as warm dense matter, is important in astrophysics, since this thermodynamic regime is encountered for instance in Jovian planets' interior. One of the most important issues is the need for accurate equations of state and transport coefficients. The Ziman formula has been widely used for the computation of the static (DC) electrical resistivity. Usually, the calculations are based on the continuum wavefunctions computed in the temperature and density-dependent self-consistent potential of a fictive atom, representing the average ionization state of the plasma (average-atom model). We present calculations of the electrical resistivity of a plasma based on the superconfiguration (SC) formalism. In this modeling, the contributions of all the electronic configurations are taken into account. It is possible to obtain all the situations between the two limiting cases: detailed configurations (a super-orbital is a single orbital) and detailed ions (all orbitals are gathered in the same super-orbital). The ingredients necessary for the calculation are computed in a self-consistent manner for each SC, using a density-functional description of the electrons. Electron exchange-correlation is handled in the local-density approximation. The momentum transfer cross-sections are calculated by using the phase shifts of the continuum electron wavefunctions computed, in the potential of each SC, by the Schroedinger equation with relativistic corrections (Pauli approximation). Comparisons with experimental data are also presented.