Band Mapping in One-Step Photoemission Theory: Multi-Bloch-Wave Structure of Final States and Interference Effects

TL;DR

This paper develops a Bloch-waves based one-step photoemission theory revealing multi-Bloch-wave structures and interference effects that impact band mapping accuracy in materials like VSe_2 and TiTe_2.

Contribution

It introduces a novel theoretical framework that accounts for interference effects and multi-Bloch-wave structures, improving understanding of photoemission processes.

Findings

Interference effects cause prominent spectral features.

Multi-Bloch-wave structures significantly influence final states.

Limitations of traditional band mapping methods are demonstrated.

Abstract

A novel Bloch-waves based one-step theory of photoemission is developed within the augmented plane wave formalism. Implications of multi-Bloch-wave structure of photoelectron final states for band mapping are established. Interference between Bloch components of initial and final states leads to prominent spectral features with characteristic frequency dispersion experimentally observed in VSe_2 and TiTe_2. Interference effects together with a non-free-electron nature of final states strongly limit the applicability of the common direct transitions band mapping approach, making the tool of one-step analysis indispensable.