Extraction of the self energy and Eliashberg function from angle resolved photoemission spectroscopy using the xARPES...

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spectroscopy

Background:

• Angle-resolved photoemission spectroscopy (ARPES) probes electron behavior in materials.
• Analyzing ARPES data to understand electron interactions is complex, especially with non-linear band structures.

Purpose of the Study:

• To develop a consistent method for extracting self-energies (electron-phonon, electron-electron, electron-impurity) from ARPES data.
• To enable analysis of curved electronic dispersions, overcoming limitations of previous methods.

Main Methods:

• Extended the maximum-entropy method for Eliashberg function extraction using Bayesian inference.
• Developed a novel Python code, xARPES, to implement these advanced analytical techniques.
• Applied the method to both model data and experimental ARPES datasets.

Main Results:

• Successfully extracted self-energies for curved dispersions, a significant improvement over linearization methods.
• Identified phonon modes in a two-dimensional electron liquid on SrTiO3.
• Achieved unprecedented agreement between Eliashberg functions for Li-doped graphene.

Conclusions:

• The new method provides a consistent and robust approach to analyzing ARPES data.
• The xARPES code facilitates the study of many-body interactions in materials.
• This work advances our understanding of electron interactions in complex materials.