Anharmonic effects on infrared spectra of GaAs and GaP

TL;DR

This paper presents a first-principles study of anharmonic effects on the infrared spectra of GaAs and GaP, highlighting temperature-dependent features and confirming predictions with experimental data.

Contribution

It introduces a detailed first-principles approach to modeling anharmonic effects on infrared spectra, incorporating recent advances in dielectric and phonon interaction theories.

Findings

Predicted infrared spectra match experimental data.

Temperature dependence of spectra is accurately captured.

Fine spectral features are explained by anharmonic effects.

Abstract

With a study of bulk GaAs and GaP, we report detailed infrared spectra and their temperature dependence from first principles. Fine features and low-temperature trends in the predicted response are confirmed by experiment. The spectra are calculated from the far-infrared through twice the frequency of the zone-center optical phonon. The treatment relies on recent developments in the theories of dielectric polarization and the phonon-phonon interaction.