Theory of dispersive optical phonons in resonant inelastic x-ray scattering experiments

The community currently lacks a complete understanding of how resonant inelastic x-ray scattering (RIXS) experiments probe the electron-phonon (\(e\)-ph) interaction in solids. For example, most theoretical models of this process have focused on dispersionless Einstein phonons. Using a recently deve...

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Bibliographic Details
Published in:arXiv.org 2022-04
Main Authors: Bieniasz, Krzysztof, Johnston, Steve, Berciu, Mona
Format: Article
Language:English
Subjects:
Data analysis
Dispersion
Electrons
Impact analysis
Inelastic scattering
Insulators
Momentum
Phonons
X-ray scattering
Online Access:Get full text
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Summary:The community currently lacks a complete understanding of how resonant inelastic x-ray scattering (RIXS) experiments probe the electron-phonon (\(e\)-ph) interaction in solids. For example, most theoretical models of this process have focused on dispersionless Einstein phonons. Using a recently developed momentum average (MA) variational approximation for computing RIXS spectra of band insulators, we examine the influence of both electron and phonon dispersion in the intermediate state of the scattering process. We find that the inclusion of either, and their mutual interplay, introduces significant momentum variations in the RIXS intensity, even for momentum-independent electron-phonon coupling. The phonon dispersion also induces nontrivial changes in the excitation line shapes, which can have a quantitative impact on the data analysis. These results highlight the considerable challenges of interpreting RIXS data in actual materials.
ISSN:2331-8422
DOI:10.48550/arxiv.2201.04577