Interplay of Voltage Control of Magnetic Anisotropy, Spin-Transfer Torque, and Heat in the Spin-Orbit-Torque Switching of Three-Terminal Magnetic Tunnel Junctions
Viola Křižáková, Eva Grimaldi, Kévin Garello, Giacomo Sala, Sébastien Couet, Gouri Sankar Kar, Pietro Gambardella
Abstract
In magnetic random-access memory, the binary memory state can be written using spin-transfer torque (STT) or spin-orbit torque (SOT), each with its advantages. Major improvements could come from using both torques, but that idea is actually not so simple. The authors study the interplay of several effects during the switching of a nanomagnet, and find that the voltage-controlled reduction of magnetic anisotropy and self-heating can minimize writing latency, whereas STT can speed up magnetization reversal. A compact analytical model separates and predicts the impact of these effects on writing efficiency, and allows optimization of design and operating conditions for combined SOT plus STT writing.