Critical current oscillations versus pureness of superconductor-ferromagnet nanoscopic multilayers

摘要

The influence of elastic electron scattering on nonmagnetic impurities in S/F multilayers to the oscillations of superconducting critical current J_c and critical temperature T_c versus the thickness of ferromagnetic layer d_F is studied. Using the quasiclassical Green function approach, we compute the electron excitation spectrum in the electrodes of S/F multilayer for an arbitrary pureness τ_iΔ (except the limit τ_iε_F ≤h, ε_F being the Fermi energy; τ_i is the scattering time of electrons on nonmagnetic impurities). Using the same assumptions, we also derive expressions for J_c and T_c. The obtained results indicate that both the J_c(d_F) and T_c (d_F) dependencies are strongly affected by the electron elastic scattering in the electrodes.