Phonon dispersion and electron-phonon interaction for from first-principles calculations

¹ Forschungszentrum Karlsruhe, Institut für Festkörperphysik P.O. Box 3640, D-76021 Karlsruhe, Germany
² BASF IT Services GmbH - D-67056 Ludwigshafen, Germany

Received: 22 May 2003
Accepted: 25 July 2003

Abstract

We present a first-principles investigation of the lattice dynamics and electron-phonon coupling of the high- superconductor within the framework of density functional perturbation theory using a mixed-basis pseudopotential method. The calculated phonon dispersion curves are in excellent agreement with Raman, infrared and neutron data. Calculation of the Eliashberg function leads to a small electron-phonon coupling in disagreement with earlier approximate treatments. Our calculations strongly support the view that conventional electron-phonon coupling is not an important contribution to superconductivity in high- materials.