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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 (≥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 [Formula: see text] is 2.5 × 106 and 4.1 × 106 A/cm2 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 JBiSb = 1.6 × 107–1.7 × 107 A/cm2. Our work demonstrates the potential of the BiSb thin film for ultralow power and fast operation of SOT-based spintronic devices.

We have developed magnetic nanowire memories with no mechanical moving parts in order to achieve the large-capacity and ultra-high data transfer rates required for spatial imaging three-dimensional television (3D-TV). In a magnetic nanowire, binary information is recorded by means of a magnetic field induced by two recording wires that are orthogonally fabricated above the nanowire. We simulated the magnetic domain formation process and found that it was formed stably in a magnetic nanowire when we utilized two recording wires. In addition, by adding a certain time difference to the current, the magnetic domains were formed with low current density. We analyzed the behavior inside the magnetic nanowire and found that magnetization reversal can be achieved at low current density when torque is applied at the appropriate time during the precession of the magnetic moment.

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