A Tunneling Investigation of the Mechanisms Determining Superconductivity in Simple Metals and Alloys

Abstract

<p> The present knowledge of lattice dynamics in particular solids is applied to the theory of strongly coupled superconductors. From existing phonon data, the product function α²(ω)F(ω) is determined in various materials, where α²(ω) is the electron-phonon coupling term, and F(ω) is the phonon density of states of that material. The Eliashberg gap equations are solved for these particular materials using this product function and predictions of the superconducting energy gap ∆(∆₀) and tunneling electron density of states N_T(ω) are made. </p> <p> Tunneling experiments are performed on selected Tℓ-Pb-Bi alloys where this phonon information is available and comparisons are made both of the predicted and obtained ∆(∆₀) and the tunneling density of states N_T(ω). </p>