Many-body calculations of plasmon and phonon satellites in angle-resolved photoelectron spectra using the cumulant expansion approach

TL;DR

This paper reviews recent advances in first-principles calculations of plasmon and phonon satellites in photoelectron spectra using the cumulant expansion approach, highlighting its accuracy and predictive power for understanding electron-boson interactions in solids.

Contribution

It introduces the fundamental concepts and reviews recent progress in first-principles cumulant expansion calculations of plasmon and phonon satellites in photoemission spectra.

Findings

Cumulant expansion approach accurately describes electron-boson coupling effects.

First-principles calculations can predict spectral features across various materials.

The method provides a unified framework for interpreting photoemission satellites.

Abstract

The interaction of electrons with crystal lattice vibrations (phonons) and collective charge-density fluctuations (plasmons) influences profoundly the spectral properties of solids revealed by photoemission spectroscopy experiments. Photoemission satellites, for instance, are a prototypical example of quantum emergent behavior that may result from the strong coupling of electronic states to plasmons and phonons. The existence of these spectral features has been verified over energy scales spanning several orders of magnitude (from 50 meV to 15-20 eV) and for a broad class of compounds such as simple metals, semiconductors, and highly-doped oxides. During the past few years the cumulant expansion approach, alongside with the GW approximation and the theory of electron-phonon and electron-plasmon coupling in solids, has evolved into a predictive and quantitatively accurate approach for the description of the spectral signatures of electron-boson coupling entirely from first principles, and it has thus become the state-of-the-art theoretical tool for the description of these phenomena. In this chapter we introduce the fundamental concepts needed to interpret plasmon and phonon satellites in photoelectron spectra, and we review recent progress on first-principles calculations of these features using the cumulant expansion method.