Magnetization switching schemes for nanoscale three-terminal spintronics devices

Utilizing spintronics-based nonvolatile memories in integrated circuits offers a promising approach to realize ultralow-power and high-performance electronics. While two-terminal devices with spin-transfer torque switching have been extensively developed nowadays, there has been a growing interest in devices with a three-terminal structure. Of primary importance for applications is the efficient manipulation of magnetization, corresponding to information writing, in nanoscale devices. Here we review the studies of current-induced domain wall motion and spin-orbit torque-induced switching, which can be applied to the write operation of nanoscale three-terminal spintronics devices. For domain wall motion, the size dependence of device properties down to less than 20nm will be shown and the underlying mechanism behind the results will be discussed. For spin-orbit torque-induced switching, factors governing the threshold current density and strategies to reduce it will be discussed. A proof-ofconcept demonstration of artificial intelligence using an analog spin-orbit torque device will also be reviewed. (C) 2017 The Japan Society of Applied Physics