Nanosecond ultralow power spin orbit torque magnetization switching driven by BiSb topological insulator

Topological insulators (TIs) are promising for spin-orbit torque (SOT) switching thanks to their giant spin Hall angle. SOT switching using TIs has been studied so far in the thermal activation regime by direct currents or relatively long pulse currents (& GE;10 ns). In this work, we studied SOT magnetization switching of (Pt/Co) multilayers with strong perpendicular magnetic anisotropy by the BiSb topological insulator in both thermal activation and fast switching regime with pulse width down to 1 ns. We reveal that the zero-Kelvin threshold switching current density J th 0 BiSb is 2.5 x 10(6) and 4.1 x 10(6) A/cm(2) for the thermal activation regime and fast switching regime in a 800 nm-wide Hall bar device via domain wall depining. From time-resolved measurements using 1 ns pulses, we find that the domain wall velocity is 430-470 m/s at J(BiSb) = 1.6 x 10(7)-1.7 x 10(7) A/cm(2). Our work demonstrates the potential of the BiSb thin film for ultralow power and fast operation of SOT-based spintronic devices.& nbsp;Published under an exclusive license by AIP Publishing.

Automated summary

Topological insulators (TIs) are potential materials for spin-orbit torque (SOT) switching due to their large spin Hall angle. This study investigated SOT magnetization switching in both thermal activation and fast switching regimes using BiSb topological insulator. The results show differences in zero-Kelvin threshold switching current density for the two regimes, and suggest the potential of BiSb thin film for ultra-low power and fast operation of SOT-based spintronic devices.