On Electron Tunneling from a Hard Superconductor in the Mixed State

Abstract

Gorkov's derivation of the Ginzburg-Landau equation from BCS theory is reformulated in such a form that one can apply it to dynamical processes involving quasiparticle excitations. As the simplest example, the method is applied to electron tunneling from an intrinsic hard superconductor in Abrikosov's mixed state. It is shown that near the transition point one obtains the usual tunneling current simply averaged over Abrikosov's distribution of energy gap. Some numerical estimates are made of the dependence of I-V characteristics on magnetic field in the case of Nb.