Phonon dispersion unfolding in the presence of heavy breaking of spatial translational symmetry

TL;DR

This paper introduces a phonon dispersion unfolding method capable of handling systems with significant breaking of spatial translational symmetry, aiding in the comparison of theoretical and experimental phonon spectra.

Contribution

The proposed method uniquely addresses heavy breaking of translational symmetry in phonon dispersion unfolding, expanding analysis capabilities for complex materials.

Findings

Validated on pure diamond, Si-substituted diamond, and diamond with C vacancies.

Effectively reveals hidden Bloch symmetries in complex systems.

Facilitates comparison between theoretical calculations and experimental spectra.

Abstract

The phonon dispersion unfolding method is useful for obtaining hidden Bloch symmetries and comparing theoretical results with experiment spectrums (e.g., inelastic neutron scattering, inelastic X-ray scattering, Raman). In this paper, we propose a method to unfold phonon dispersions. The main advantage of this method is the ability to handle systems with heavy breaking of spatial translational symmetry. Its validity is tested by pure diamond, diamond with Si substitution, and diamond with C vacancies.