Quantitative analysis of Sr2RuO4 ARPES spectra: Many-body interactions in a model Fermi liquid

TL;DR

This paper presents a novel fitting method for ARPES spectra of Sr2RuO4, enabling precise extraction of many-body interaction parameters and confirming Fermi liquid behavior through linewidth and self-energy analysis.

Contribution

It introduces a quantitative fitting procedure that deconvolves ARPES spectra to analyze many-body interactions in Sr2RuO4, providing the first complete ARPES-based Fermi liquid characterization.

Findings

ARPES linewidth narrower than binding energy, indicating quasiparticles.

Electron-electron scattering decreases with Fermi energy as expected in Fermi liquids.

Self-energy magnitude aligns with DC transport measurements.

Abstract

ARPES spectra hold a wealth of information about the many-body interactions in a correlated material. However, the quantitative analysis of ARPES spectra to extract the various coupling parameters in a consistent manner is extremely challenging, even for a model Fermi liquid system. We propose a fitting procedure which allows quantitative access to the intrinsic lineshape, deconvolved of energy and momentum resolution effects, of the correlated 2-dimensional material Sr2RuO4. For the first time in correlated 2-dimensional materials, we find an ARPES linewidth that is narrower than its binding energy, a key property of quasiparticles within Fermi liquid theory. We also find that when the electron-electron scattering component is separated from the electron-phonon and impurity scattering terms it decreases with a functional form compatible with Fermi liquid theory as the Fermi energy is approached. In combination with the previously determined Fermi surface, these results give the first complete picture of a Fermi liquid system via ARPES. Furthermore, we show that the magnitude of the extracted imaginary part of the self-energy is in remarkable agreement with DC transport measurements.