Raman Insights into the Phonon Dynamics of Weyl Semimetals*

Weyl semimetals (WSM) are a recently realized class of topological materials with low energy electronic excitations characterized by a three-dimensional, linear dispersion. While much focus has been directed at characterizing and understanding the electronic properties of various WSMs, little attention has been paid to the vibrational properties. In the WSMs NbAs and TaAs such considerations are crucial for understanding the anomalously high mobility and thermal response. We present temperature and polarization dependent Raman spectra which reveal anomalous lineshapes, as well as deviations from standard anharmonic behavior.