Unbiased Analysis of Super/Ferro Bilayer Physics

S/F bilayer physics has been studied for some time now. With a large number of unknown and seemingly-known parameters, some values are traditionally and understandably assumed to be fixed quantities. In particular, the exchange energy, $E_{ex}/k_B$, is believed to be comparable to the Curie temperature. We analyze the data assuming only that the Fermi velocity $v_F$ in F and the density of states, $2N_S(0)$, in S are known. Fitting $T_c$ vs. $d_F$ with the dirty-limit theory, we determine the interface resistance, $R_b$, the ratio $E_{ex}/\rho_F\ell_F$, and the ferromagnetic coherence length $\xi_F$. For physically plausible values of $\rho_F\ell_F$, the dephasing rate of cooper pairs in F is 10 times smaller than expected from the known Curie temperature of F. We propose that dephasing is mitigated by spin-orbit scattering. We also find that the transmission probability for electrons striking the F/S interface is much less than unity.