Chiral phonons in chiral and achiral materials

We present our recent findings on the discovery of chiral phonons in intrinsically chiral materials such as α-HgS [1], Te [2], and related compounds, revealed through circularly polarized Raman scattering and first-principles calculations. These chiral phonons not only carry angular momentum but also exhibit chirality characterized by the pseudoscalar quantity G0. Furthermore, we explore the possibility of exciting chiral phonons in achiral materials, irrespective of the presence or absence of spatial inversion symmetry.

[1] K. Ishito et al., Nature Phys. 19, 35 (2023).

[2] K. Ishito et al., Chirality 35, 338 (2023).