General analysis of the ARPES line shape for strongly correlated electron systems

TL;DR

This paper analyzes the ARPES line shape in strongly correlated electron systems, highlighting the role of a strength operator in explaining momentum asymmetry observed in spectra, which reflects electron correlation strength.

Contribution

It introduces a comprehensive analysis of the Green function structure, emphasizing the significance of the strength operator in ARPES spectral asymmetry.

Findings

The spectral function's asymmetry is influenced by the strength operator.

The odd momentum contribution explains the observed ARPES asymmetry.

Spectral asymmetry can serve as a measure of electron correlation strength.

Abstract

In many cases the standard perturbation approach appears to be too simple to describe precisely the angle resolved photoemission spectrum of strongly correlated electron system. In particular, to describe the momentum asymmetry observed in photoemission spectra of high-Tc cuprates a phenomenological approach based on extremely correlated Fermi-liquid model has been recently introduced. In this paper we analyze the general structure of the Green function of quasiparticles in strongly correlated electron systems and stress that it is defined not only by the self-energy of Hubbard quasiparticles but also by a strength operator. We show that the later leads to an additional odd momentum contribution to the spectral function and alone can explain the observed asymmetry. So, the asymmetry of the ARPES spectra can be a measure of the strength of electron correlations in materials.