Third-order density-functional perturbation theory yields the terahertz/far-infrared absorption spectra for silicon and germanium, including all two-phonon combination and difference features. Temperature-dependent spectra are compared to available experimental results. Critical-point analysis is used to identify the branch and wave-vector indices of many features.
Citation: Physical Review B (Condensed Matter and Materials Physics)
Issue: No. 5
Pub Type: Journals
absorption spectrum, critical point, germanium, phonon, silicon, terahertz