Spin‐mixing conductances: The influence of disorder

Abstract

1 Introduction and theory If a current incident on a thin ferromagnetic (FM) layer is polarized noncollinearly with respect to the layer magnetization, it exerts a spin-transfer torque on the magnetic layer and may change its magnetization direction [1]. This phenomenon attracts ongoing interest because of its high application potential. Spin-transfer torque exerted on a magnetic layer can be viewed as a linear response to the spin accumulation inside an adjacent non-magnetic layer. The complex spin-mixing conductance [2] provides -together with the usual spin-resolved conductances in current-perpendicularto-plane (CPP) geometry -complete information on a linear response of particle and spin currents due to the bias and spin accumulation in the adjacent metals.Here we use the recently introduced ab initio materialspecific approach to this observable [3] based on nonequilibrium Green's functions formalism. The numerical implementation employs the local spin density approximation (LSDA) and the tight-binding linear muffin-tin orbital (TB-LMTO) method [4]. The spin-mixing conductance

Landauer theory of ballistic torkances in noncollinear spin valves

“…16 The particular value of the oscillation period follows from a special shape of the spinpolarized Fermi surface of bulk fcc Ni. 16 The oscillations of C mix have been found fairly stable against Cu-Ni interdiffusion at the interfaces; 25 the same stability can be thus expected for the torkance oscillations in the spin valve. The relative stability can be understood as an effect of the large oscillation period (∼ 12 ML): intermixing confined to a very few atomic planes at interfaces reduces the oscillation amplitude rather weakly.…”

Out-of-plane spin-transfer torques: First-principles study

“…The second critical factor is the thickness of the free layer, for which the optimal value must be achieved with high accuracy in order to reach the desired ratio between the out-of-plane and inplane component. It is also important that this effect is only weakly smeared by interface disorder [13].…”

“…A high Im C mix is apparently quite subtle feature and ab initio calculations are needed to predict it. Fortunately it is stable against small antisite disorder present in Co 2 MnSi [13].…”