Phenomenological Modeling of Photoemission Spectra in Strongly Correlated Electron Systems

TL;DR

This paper introduces a phenomenological model with an analytical self-energy formula to interpret photoemission spectra in strongly correlated electron systems, fitting experimental data to extract physical parameters.

Contribution

It presents a simple analytical self-energy model that captures both coherent and incoherent spectral features, enabling interpretation of experimental photoemission data.

Findings

Successfully fitted La$_{1-x}$Sr$_x$TiO$_3$ spectra for various x values.

Extracted effective mass and Hubbard interaction parameters from fits.

Provided insights into spectral weight distribution in correlated systems.

Abstract

A phenomenological approach is presented that allows one to model, and thereby interpret, photoemission spectra of strongly correlated electron systems. A simple analytical formula for the self-energy is proposed. This self-energy describes both coherent and incoherent parts of the spectrum (quasiparticle and Hubbard peaks, respectively). Free parameters in the expression are determined by fitting the density of states to experimental photoemission data. An explicit fitting is presented for the La$_{1-x}$Sr$_x$TiO$_3$ system with $0.08 \le x \le 0.38$. In general, our phenomenological approach provides information on the effective mass, the Hubbard interaction, and the spectral weight distribution in different parts of the spectrum. Limitations of this approach are also discussed.