RELATIVISTIC THEORY OF SUPERCONDUCTIVITY

A relativistic generalization of the Bogolubov-de Gennes equations is derived where the particle and hole amplitudes are Dirac spinors. in the weakly relativistic limit one obtains, besides the usual spin-orbit, Darwin and kinetic energy corrections, a new ''spin-orbit'' and a new ''Darwin'' term involving the pair potential in place of the electrostatic potential. The results indicate the significance of the relativistic corrections for superconductors with a high Fermi velocity, a small coherence length or heavy elements in the lattice.