Dependence of Tc on the q and w structure of the spin-fluctuation spectrum of YBCO6.6

A phenomenological spin-fuctuation analysis , based upon inelastic neutron scattering (INS) and angular resolved spectroscopy (ARPES) data for YBCO6.6(Tc =61K), is used to calculate the functional derivative of the d-wave eigenvalue of the linearized gap equation with respect to chi"(q,w)) at 70K. For temperatures near Tc, the variation of Tc with respect to chi"(q,w) is proportional to this functional derivative. Based on this, we discuss how different parts of the q and w spin-fuctuation spectrum of YBCO6.6 contribute to Tc.