Acoustic phonons represent a versatile platform for the study of wave dynamics and localized excitations featuring two main advantages with respect to the electronic and optical counterparts:

First, their short wavelengths (few nanometers at 100 GHz-THz frequencies) allow the experimental implementation of very large systems which may be considered infinite for all practical means.

Second, the relatively slow speed of sound renders the amplitude and phase of the acoustic wave fully accessible. Topological acoustics, Anderson co-localization of acoustic phonons and visible photons, Bloch oscillations are a few examples of the physics explored in this research line.

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