Tunneling in Bi2212: Eliashberg Analysis of Spectral Dip Feature

Eliashberg theory, extended to a d-wave symmetric gap function, has been used to quantitatively fit a published tunneling spectrum of Bi2212. The shape, location and strength of the high bias spectral dip feature has been adequately reproduced using a single-peak α^2F(ω) centered at 36.5 meV. The spectral function self consistently determines the measured gap parameter of 32 meV. Along with doping dependent measurements these results point toward the resonance spin excitation as the origin of the bosonic spectrum.