Atomistic visualization of anisotropic wave propagation in crystals

Presented here is a new molecular dynamics simulation approach for visualizing multidimensional acoustic wave-packet propagation in anisotropic materials. This approach allows examination of longitudinal wave propagation in a selected frequency range and may also be extended to track transverse motions. The obtained results agree with analytical predictions and experimental measurements of quasilongitudinal wave front propagation in the literature. Additionally, spectral analysis reveals minor levels of frequency redistribution as the wave packet propagates, which is indicative of phonon-phonon scattering. The present approach provides new capabilities for phonon-focusing studies and offers an alternative to existing experimental and Monte Carlo techniques used for these studies.