Correlation of tunneling spectra in Bi2Sr2CaCu2O8+δ with the resonance spin excitation -: art. no. 067005

New break-junction tunneling data are reported in Bi2Sr2CaCu2O8+delta over a wide range of hole concentration from underdoped (T-c = 74 K) to optimal doped (T-c = 95 K) to overdoped (T-c = 48 K). The conductances exhibit sharp dips at a voltage, Omega /e, measured with respect to the superconducting gap. Clear trends are found such that the dip strength is maximum at optimal doping and that fl scales as 4.9 kT(c) over the entire doping range. These features link the dip to the resonance spin excitation and suggest quasiparticle interactions with this mode are important for superconductivity.