Chiral phonons are groups of atoms that move in a circular direction when excited by an energy source, such as heat. As the phonons move through a material, they propagate that circular motion, or angular momentum, through the material. The angular momentum serves as the source of spin, and the...
Source: [Phys.org](https://phys.org/news/2026-08-electric-field-reverses-phonon-chirality.html)