@article{20432,
  abstract     = {A rapidly increasing body of work reporting phenomena associated with lattice vibrations carrying angular momentum has led to the emergence of the field of chiral phonons. Some of these properties, such as the phonon magnetic moment, also occur in achiral phonons that are circularly or elliptically polarized, while the presence of chirality has additional implications for the types of interaction allowed between the phonons and light, electrons and other quasiparticles. In this Perspective we introduce a framework for classifying phonons with angular momentum, and provide illustrations of the different types using examples from the recent literature. Specifically, we suggest the term ‘axial phonon’ to encompass all phonons that carry angular momentum, real or pseudo, and reserve the term ‘chiral phonon’ for those phonons that break improper rotational symmetry. We hope that this scheme provides clarification on the matter of phonon chirality and will serve as a guide for future research.},
  author       = {Juraschek, Dominik M. and Geilhufe, R. Matthias and Zhu, Hanyu and Basini, Martina and Baum, Peter and Baydin, Andrey and Chaudhary, Swati and Fechner, Michael and Flebus, Benedetta and Grissonnanche, Gael and Kirilyuk, Andrei I. and Lemeshko, Mikhail and Maehrlein, Sebastian F. and Mignolet, Maxime and Murakami, Shuichi and Niu, Qian and Nowak, Ulrich and Romao, Carl P. and Rostami, Habib and Satoh, Takuya and Spaldin, Nicola A. and Ueda, Hiroki and Zhang, Lifa},
  issn         = {1745-2481},
  journal      = {Nature Physics},
  pages        = {1532--1540},
  publisher    = {Springer Nature},
  title        = {{Chiral phonons}},
  doi          = {10.1038/s41567-025-03001-9},
  volume       = {21},
  year         = {2025},
}