Origin of superconductivity in layered centrosymmetric LaNiGa2

Abstract

We have examined the origin of superconductivity in layered centrosymmetric LaNiGa2 by employing a linear response approach based on the density functional perturbation theory. Our results indicate that this material is a conventional electron-phonon superconductor with intermediate level of coupling strength, with the electron-phonon coupling parameter of 0.70, and the superconducting critical temperature of 1.90 K in excellent accordance with experimental value of 1.97 K. The largest contribution to the electron-phonon coupling comes from the La d and Ga p electrons near the Fermi energy and the B3g phonon branch resulting from vibrations of these atoms along the Γ-Z symmetry line in the Brillouin zone.