The last paper published by Dr. Juan Sebastian Reparaz studing phonon transport was awarded with Editor’s pick
The article entitled “Phonon transport in the gigahertz to terahertz range: Confinament, topology and second sound” focuses about, with authors words: we emphasize experimental works and particularly the techniques of BLS, FD-TR, and TD-TR. We discuss how the recently developed pumped-BLS approach can be used to study acoustic Anderson localization, one-way transport in acoustic diodes, and topological acoustics. In the discussion of BLS, we omit its use on the biomedical secto and on spintronics (magnonics). Finally, we turn our attention to thermal waves, otherwise known as Second Sound. In the hydrodynamic regime, the temperature field is partially transported by thermal waves, as given by the hyperbolic heat equation. We provide a historical overview of the field, emphasizing the recent developments in experiments, theoretical aspects, and numerical experiments.