Temperature and excitation energy dependence of Raman scattering in the nodal-line semimetal ZrAs2

We present a Raman study of ZrAs₂ single crystals, a nodal-line semimetal with symmetry-enforced Dirac-like band crossings. We identified the symmetry of phonon modes by polarized light measurements and comparison with calculated phonon frequencies. Significant dependence of peak intensities on the excitation wavelength was observed, indicating quantum interference effects. Phonon peaks in the spectra were superimposed on the electronic background, with quasielastic scattering observed for the 785-nm excitation. The temperature dependence of phonon peaks' linewidth indicates that the electron-phonon coupling plays an essential role in phonon decay.