On the inversion of tunneling characteristics in superconductors with spin fluctuations

Abstract

We have calculated the current-voltage characteristics of a superconductor with spin fluctuations explicitly included in the kernels of the Eliashberg equation along with the electron-phonon spectral density α 2( ω) F( ω). These characteristics are then inverted using the method outlined by Galkin et al. to get an effective electron-phonon spectral density assuming no paramagnons are present in the Eliashberg equations during the inversion procedure. The effective electron-phonon spectral density found in this way is, to an excellent approximation, a scaling factor of 1 (1+λ sf) times the original α 2( ω) F( ω), with λ sf the paramagnon mass renormalization.