Enhanced Perpendicular Spin Transfer Torque in Magnetic Multilayers With a Capping Layer

In this paper, we model the effects of the physical properties of the capping layer, such as spin diffusion length (l
_sf

^cap
), resistivity (¿
_cap
), and interfacial conductance (G
_¿

^cap
, G
_¿

^cap
) on the spin transport across a pseudo-spin-valve (PSV) structure. In particular, we investigate how the properties of the capping layer can be modified in order to enhance the perpendicular component (¿
_¿
) of the spin transfer torque vis-a¿-vis the inplane (¿
_¿
) component. The results suggest that the capping layer can serve as an effective medium for tuning the ratio of ¿
_¿
to ¿
_¿
by varying its physical properties.