Theory of Anisotropic Electron–Phonon Interaction in Copper I. Electron–Phonon Matrix Elements

Abstract

AbstractThe electron–phonon interaction in copper is calculated on the basis of realistic wave functions and taking into account all anisotropies of the system. The electron wave functions are derived from a combined interpolation scheme, in which the wave functions are assumed to be composed of both, plane waves and Bloch sums of atomic d‐functions. Because of the “pseudo” character of the wave functions thus obtained, these have to be combined with a pseudopotential in order to render the correct electron–phonon matrix elements; this contrasts with an earlier paper in the literature. Taking a slightly modified Cohen‐Heine pseudopotential and the plane‐wave contributions only, leads to a satisfactory agreement between calculated and observed anisotropic quantities. The other contributions to the matrix elements are critically discussed. Applications will be considered in a subsequent paper.