Fast Switching And Signature Of Efficient Domain Wall Motion Driven By Spin-Orbit Torques In A Perpendicular Anisotropy Magnetic Insulator/Pt Bilayer

We report fast and efficient current-induced switching of a perpendicular anisotropy magnetic insulator thulium iron garnet by using spin-orbit torques (SOT) from the Pt overlayer. We first show that, with quasi-DC (10 ms) current pulses, SOT-induced switching can be achieved with an external field as low as 2 Oe, making TmIG an outstanding candidate to realize efficient switching in heterostructures that produce moderate stray fields without requiring an external field. We then demonstrate deterministic switching with fast current pulses (<= 20 ns) with an amplitude of similar to 10(12) A/m(2), similar to all-metallic structures. We reveal that, in the presence of an initially nucleated domain, the critical switching current is reduced by up to a factor of five with respect to the fully saturated initial state, implying efficient current-driven domain wall motion in this system. Based on measurements with 2 ns-long pulses, we estimate the domain wall velocity of the order of similar to 400 m/s per j = 10(12) A/m(2). Published by AIP Publishing.