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Effects of electron-phonon coupling on absorption spectrum: K edge of hexagonal boron nitride

Autor(en)
Ferenc Karsai, Moritz Humer, Flage-Larsen Espen, Blaha Peter, Georg Kresse
Abstrakt

A detailed analysis of the theoretical x-ray absorption near-edge structures (XANES) for the boron and nitrogen K edge in hexagonal boron nitride (h-BN) employing density-functional theory calculations is presented. The supercell core-hole method and the Bethe-Salpeter equation are used for the description of electron-hole interactions. The calculations are carried out with two different codes, the vasp and the wien2k codes, employing the projector augmented-wave and the full-potential linear augmented-plane-wave methods, respectively. We find close agreement between spectra obtained from the two codes and between calculations using the supercell core-hole method and the Bethe-Salpeter approach. All our calculations, as well as previous calculations using the ground-state structure, yield a single 2pσ∗ peak in the boron K-edge spectrum and hence fail to describe the experimental double-peak structure. We find that the inclusion of electron-phonon interactions is crucial to obtain the experimentally observed double-peak structure. We include these effects fully parameter free and ab initio using a one-shot sampling method and obtain excellent agreement with experiment.

Organisation(en)
Computergestützte Materialphysik
Externe Organisation(en)
SINTEF The Foundation for Scientific and Industrial Research at the Norwegian Institute of Technology (NTH), Technische Universität Wien, Universität Wien
Journal
Physical Review B
Band
98
Anzahl der Seiten
10
ISSN
2469-9950
DOI
https://doi.org/10.1103/PhysRevB.98.235205
Publikationsdatum
12-2018
Peer-reviewed
Ja
ÖFOS 2012
103018 Materialphysik
Schlagwörter
ASJC Scopus Sachgebiete
Electronic, Optical and Magnetic Materials, Condensed Matter Physics
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/595a5614-e6cb-4290-81b5-366ebe1fce60