Comparing two isostructural Weyl semimetals with respect to phonon dynamics and resonance phenomena

The isostructural Weyl semimetals PdGa and RhSi allow to probe the response of lattice and electronic degrees of freedom to symmetry, in particular the role of chirality in anomalous electron phonon coupling. We observe an unconventional anharmonicity in the temperature dependence of phonon frequency and linewidth. Furthermore, resonance phenomena of the phonon intensities are studied and related to different electronic energy scales. We also notice an effect of magnetic fields on the phonon intensity if light polarizations include optical spin (SAM, helicity) and orbital angular momentum (OAM, chirality).