Phonon anharmonic frequency shift induced by four-phonon scattering calculated from first principles
| Autor: | Xiulin Ruan, Xiaolong Yang, Tianli Feng |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Physics
Condensed Matter - Materials Science Condensed matter physics Phonon scattering Scattering Phonon Anharmonicity Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences General Physics and Astronomy 02 engineering and technology Radius 021001 nanoscience & nanotechnology 01 natural sciences Inelastic neutron scattering Brillouin zone Condensed Matter::Materials Science Condensed Matter::Superconductivity 0103 physical sciences Harmonic 010306 general physics 0210 nano-technology |
| Zdroj: | Journal of Applied Physics. 124:145101 |
| ISSN: | 1089-7550 0021-8979 |
| Popis: | Phonon energies at finite temperatures shift away from their harmonic values due to anharmonicity. In this paper, we have realized the rigorous calculation of phonon energy shifts of silicon by three and four-phonon scattering from first principles. The anharmonic fourth-order force constants are calculated by considering up to the fifth nearest neighbors. The results agree reasonably well with available data from inelastic neutron scattering throughout the Brillouin zone. Surprisingly, the frequency shifts of optical phonon modes near the $\Gamma$ point are sensitive to the cutoff radius of the fourth-order force constants, in contrast to the four-phonon scattering rates, which nearly saturate when considering the second nearest neighbors. We have also compared the results with ab initio molecular dynamics simulations and found that the higher order of anharmonicity is important for optical phonons. Our work provides critical insight into the anharmonic phonon frequency shift and will have significant impact on the thermal and optical applications. |
| Databáze: | OpenAIRE |
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