Beyond the single-site approximation modeling of electron-phonon coupling effects on resonant inelastic X-ray scattering spectra
Resonant inelastic X-ray scattering (RIXS) is used increasingly for characterizing low-energy collective excitations in materials. RIXS is a powerful probe, which often requires sophisticated theoretical descriptions to interpret the data. In particular, the need for accurate theories describing...
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| Format: | Article |
| Language: | English |
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SciPost
2021-09-01
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| Series: | SciPost Physics |
| Online Access: | https://scipost.org/SciPostPhys.11.3.062 |
| _version_ | 1818922593980252160 |
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| author | Krzysztof Bieniasz, Steven Johnston, Mona Berciu |
| author_facet | Krzysztof Bieniasz, Steven Johnston, Mona Berciu |
| author_sort | Krzysztof Bieniasz, Steven Johnston, Mona Berciu |
| collection | DOAJ |
| description | Resonant inelastic X-ray scattering (RIXS) is used increasingly for
characterizing low-energy collective excitations in materials. RIXS is a
powerful probe, which often requires sophisticated theoretical descriptions to
interpret the data. In particular, the need for accurate theories describing
the influence of electron-phonon ($e$-p) coupling on RIXS spectra is becoming
timely, as instrument resolution improves and this energy regime is rapidly
becoming accessible. To date, only rather exploratory theoretical work has been
carried out for such problems. We begin to bridge this gap by proposing a
versatile variational approximation for calculating RIXS spectra in weakly
doped materials, for a variety of models with diverse $e$-p couplings. Here, we
illustrate some of its potential by studying the role of electron mobility,
which is completely neglected in the widely used local approximation based on
Lang-Firsov theory. Assuming that the electron-phonon coupling is of the
simplest, Holstein type, we discuss the regimes where the local approximation
fails, and demonstrate that its improper use may grossly \textit{underestimate}
the $e$-p coupling strength. |
| first_indexed | 2024-12-20T01:56:01Z |
| format | Article |
| id | doaj.art-777c9562fdc0405685086df025e489bd |
| institution | Directory Open Access Journal |
| issn | 2542-4653 |
| language | English |
| last_indexed | 2024-12-20T01:56:01Z |
| publishDate | 2021-09-01 |
| publisher | SciPost |
| record_format | Article |
| series | SciPost Physics |
| spelling | doaj.art-777c9562fdc0405685086df025e489bd2022-12-21T19:57:29ZengSciPostSciPost Physics2542-46532021-09-0111306210.21468/SciPostPhys.11.3.062Beyond the single-site approximation modeling of electron-phonon coupling effects on resonant inelastic X-ray scattering spectraKrzysztof Bieniasz, Steven Johnston, Mona BerciuResonant inelastic X-ray scattering (RIXS) is used increasingly for characterizing low-energy collective excitations in materials. RIXS is a powerful probe, which often requires sophisticated theoretical descriptions to interpret the data. In particular, the need for accurate theories describing the influence of electron-phonon ($e$-p) coupling on RIXS spectra is becoming timely, as instrument resolution improves and this energy regime is rapidly becoming accessible. To date, only rather exploratory theoretical work has been carried out for such problems. We begin to bridge this gap by proposing a versatile variational approximation for calculating RIXS spectra in weakly doped materials, for a variety of models with diverse $e$-p couplings. Here, we illustrate some of its potential by studying the role of electron mobility, which is completely neglected in the widely used local approximation based on Lang-Firsov theory. Assuming that the electron-phonon coupling is of the simplest, Holstein type, we discuss the regimes where the local approximation fails, and demonstrate that its improper use may grossly \textit{underestimate} the $e$-p coupling strength.https://scipost.org/SciPostPhys.11.3.062 |
| spellingShingle | Krzysztof Bieniasz, Steven Johnston, Mona Berciu Beyond the single-site approximation modeling of electron-phonon coupling effects on resonant inelastic X-ray scattering spectra SciPost Physics |
| title | Beyond the single-site approximation modeling of electron-phonon coupling effects on resonant inelastic X-ray scattering spectra |
| title_full | Beyond the single-site approximation modeling of electron-phonon coupling effects on resonant inelastic X-ray scattering spectra |
| title_fullStr | Beyond the single-site approximation modeling of electron-phonon coupling effects on resonant inelastic X-ray scattering spectra |
| title_full_unstemmed | Beyond the single-site approximation modeling of electron-phonon coupling effects on resonant inelastic X-ray scattering spectra |
| title_short | Beyond the single-site approximation modeling of electron-phonon coupling effects on resonant inelastic X-ray scattering spectra |
| title_sort | beyond the single site approximation modeling of electron phonon coupling effects on resonant inelastic x ray scattering spectra |
| url | https://scipost.org/SciPostPhys.11.3.062 |
| work_keys_str_mv | AT krzysztofbieniaszstevenjohnstonmonaberciu beyondthesinglesiteapproximationmodelingofelectronphononcouplingeffectsonresonantinelasticxrayscatteringspectra |