Spin-memory loss at Co/Ru interfaces

Abstract

We have determined the spin-memory-loss parameter ${\ensuremath{\delta}}_{\text{Co/Ru}}$ by measuring the transmission of spin-triplet and spin-singlet Cooper pairs across Co/Ru interfaces in Josephson junctions and by current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) techniques. The probability of spin-memory loss at the Co/Ru interface is $[1\ensuremath{-}\text{exp}(\ensuremath{-}{\ensuremath{\delta}}_{\text{Co/Ru}})]$. From the CPP-MR, we obtain ${\ensuremath{\delta}}_{\text{Co/Ru}}=0.{34}_{\ensuremath{-}0.02}^{+0.04}$, which is in good agreement with ${\ensuremath{\delta}}_{\text{Co/Ru}}=0.35\ifmmode\pm\else\textpm\fi{}0.08$ obtained from spin-triplet transmission. For spin-singlet transmission, we have ${\ensuremath{\delta}}_{\text{Co/Ru}}=0.64\ifmmode\pm\else\textpm\fi{}0.05$, which is different from that obtained from CPP-GMR and spin-triplet transmission. The source of this difference is not understood.