Extended Data Fig. 7: Skyrmion Motion in FL Wires.
(a) In situ MFM image of 2 × 10 µm FL wire device (stack and fabrication details in Methods) at µ0H ≃ 74 mT. Highlighted box shows region of interest for c-e. (b) Schematic of experimental protocol: current pulses of alternating polarity, J ≃ ±(3.5 − 6.5) × 1011 A/m2, were applied sequentially, and the device was imaged before and after each pulse. (c) Top: representative zoom-in MFM images acquired before and after successive current pulses of opposite polarities (J ≃ 6.3 × 1011 A/m2). Small circles indicate positions of a few representative skyrmions across images; large, dashed circle identifies a prominent defect used for registration. Bottom: tracked positions of skyrmions across pulses (representative skyrmions highlighted), with arrows indicating extent of motion. (d) Polar plot of skyrmion motion statistics for µ0H ≃ 74 mT, compiled for selected J (data for J < 0 rotated by 180◦), showing a spread of velocities and deflections. (e) Plot of the average skyrmion velocity, ⟨vS⟩ against J. Error bars represent standard deviation.