High speed in spin-torque-based magnetic memory using magnetic nanocontacts



Magnetization switching by a spin-polarized current in perpendicular anisotropy devices with magnetic nanocontact (NC) is investigated using a micromagnetic formalism. The critical switching current (icr) and switching time (τ0) can be reduced when a soft layer is exchange coupled to the NC. The study reveals that devices with fewer NCs have smaller icr compared to those with a large number. Furthermore, τ0 for nanoconstricted devices is almost constant with anisotropy field (Hk), in contrast to devices without NCs that show an exponential increase with Hk. This suggests that nanoconstricted devices could be used to improve thermal stability, while reducing icr and τ0. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)