Macrospin modeling of sub-ns pulse switching of perpendicularly magnetized free layer via spin-orbit torques for cryogenic memory applications

作者：Park Junbo^*; Rowlands G E; Lee O J; Ralph D C; Buhrman R A

来源：Applied Physics Letters, 2014, 105(10): 102404.

DOI：10.1063/1.4895581

We model, using the macrospin approximation, the magnetic reversal of a perpendicularly magnetized nanostructured free layer formed on a normal, heavy-metal nanostrip, subjected to spin-orbit torques (SOTs) generated by short (<= 0.5 ns) current pulses applied to the nanostrip, to examine the potential for SOT-based fast, efficient cryogenic memory. Due to thermal fluctuations, if solely an anti-damping torque is applied, then, for a device with sufficiently low anisotropy (H-anis(0)similar to 1 kOe) suitable for application in cryogenic memory, a high magnetic damping parameter (alpha similar to 0.1 - 0.2) is required for reliable switching over a significant variation of pulse current. The additional presence of a substantial field-like torque improves switching reliability even for low damping (alpha <= 0.03).

• 出版日期2014-9-8