Fig. 3: Current-induced behavior of magnetic skyrmions and their skyrmion Hall effect with and without the excitation of SAW.

a Sequential MOKE images of magnetic ___domain patterns of Co/Pd/Co/Pd/Co/Pt multilayer under the current pulse applications at H_z = 10.86 Oe. Note that different skyrmions are characterized by different colors. Current density used to drive the skyrmion movement is 2.5 × 10¹⁰ A m⁻² The duration of current pulses is 50 µs. b The movement trajectory of selected skyrmions in (a). c Phase diagram of the skyrmion Hall angle θ_sk as a function of current density measured with and without SAWs for skyrmions with topological charge Q = +1 and Q = –1. The skyrmions in the sample without SAW are generated through the thermal effect by fabricating a heater on the side of the channel. Each data point is an average of measurements obtained by tracking the movement of several independent skyrmions, with the error bars representing the standard deviation. The insets show the magnetic configurations of the skyrmions with opposite topological charge. Note that H_z = +9.1 Oe (–8.8 Oe) for Q = +1 (–1) with SAWs and H_z = +0.8 Oe (–1.0 Oe) for Q = +1 (–1) without SAW. The RF signal of P = 21 dBm was applied during all the current-driven measurements.