Law of Corresponding States in Superconductivity

Abstract

It is shown by means of a crude calculation that a refined version of the Bardeen-Cooper-Schrieffer theory of superconductivity in which the energy gap function $\ensuremath{\mu}(\ensuremath{\nu})$ would not be approximated by a constant would give very nearly the same relation between ${H}_{0}$, the critical field at $T=0$; $2\ensuremath{\mu}(0)$, the energy gap; and $N(0)$, the density of states at the Fermi surface. Agreement between the theory and experiment is found for the cases of Al, Sn, Hg, and Pb although the experimental error is large for Hg. For the case of Pb, this is the first agreement between the theory and experiment with regard to the thermodynamic variables.