Calculation of phonon-induced gap anisotropy in superconducting Zn

Abstract

Leavens and Carbotte have given a microscopic theory of gap anisotropy applicable to the case of a weak-coupling superconductor. The theory relates the anisotropy in the gap directly to Fermi surface anisotropy and anisotropy in the electron-phonon interaction. We present detailed calculations of the phonon-induced anisotropy for the case of Zn. The gap is calculated for a dense set of points on the irreducible one-twenty-fourth of the Fermi surface. From this information the average gap and the pure single-crystal critical temperature are computed and compared with the dirty-limit case. The specific heat and spin-lattice relaxation are calculated as examples of thermodynamic properties.