Valence Fluctuations and Quasiparticle Multiplets in Pu Chalcogenides and Pnictides

TL;DR

This paper investigates the electronic spectra of plutonium chalcogenides and pnictides using advanced computational methods, revealing valence fluctuations, quasiparticle multiplets, and the impact of valence state changes on material properties.

Contribution

It introduces a combined LDA+DMFT approach with valence histograms and slave-boson calculations to analyze valence fluctuations and quasiparticle features in Pu compounds.

Findings

Chalcogenides are mixed-valent with temperature-dependent density of states.

Identification of triplet quasiparticle peaks below the Fermi level.

Prediction of reflected peaks above the Fermi level in spectra.

Abstract

The spectra of Pu chalcogenides and pnictides are computed with LDA+DMFT and interpreted with the aid of valence histograms and slave-boson calculations. We find the chalcogenides are mixed-valent ($n_f = 5.2$) materials with a strongly $T$-dependent low-energy density of states and a triplet of quasiparticle peaks below the Fermi level. Furthermore, we predict a doublet of reflected peaks above the Fermi level. In the pnictides, the raising of $f^6$ states relative to $f^5$ suppresses valence fluctuations, resulting in integral-valent ($n_f = 5.0$) local moment metals.