A Raman probe of phonons and electron–phonon interactions in the Weyl semimetal NbIrTe4
Iraj Abbasian Shojaei, Seyyedesadaf Pournia, Congcong Le, Brenden R. Ortiz, Giriraj Jnawali, Fu‐Chun Zhang, Stephen D. Wilson, Howard E. Jackson, Leigh M. Smith
Abstract
has been proposed to be a Type-II Weyl semimetal with 8 pairs of opposite Chirality Weyl nodes which are very close to the Fermi energy. We show using polarized angular-resolved micro-Raman scattering at two excitation energies that we can extract the phonon mode dependence of the Raman tensor elements from the shape of the scattering efficiency versus angle. This van der Waals semimetal with broken inversion symmetry and 24 atoms per unit cell has 69 possible phonon modes of which we measure 19 modes with frequencies and symmetries consistent with Density Functional Theory calculations. We show that these tensor elements vary substantially in a small energy range which reflects a strong variation of the electron-phonon coupling for these modes.