Fig. 5

Magnetic force microscopy (MFM) imaging of the probe-driven interaction between two individual skyrmions. Sequence of MFM images illustrating the dynamics of probe-driven skyrmion interaction in Pt/CoFeB/MgO multilayer under an applied perpendicular field \({H}_{{\rm{z}}}\) = 71 mT. a, c Two individual skyrmions, marked by S\({}_{1}\) and S\({}_{2}\), are imaged in single pass MFM mode at a lift height \(\Delta z\) = 145 nm, with the topography acquired separately at \({H}_{{\rm{z}}}\) = 50 mT. The dashed arrows are guides for the eye indicating the trajectories followed by the skyrmions during the probe-driven interaction. b Skyrmion S\({}_{1}\) is pushed against skyrmion S\({}_{2}\) by the probe stray field during the topography line scans of a standard two pass MFM scan (also with \(\Delta z\) = 145 nm). Skyrmion S\({}_{1}\) avoids the collision with skyrmion S\({}_{2}\) by jumping abruptly towards the right. The directions of fast and slow scan axes are marked by the arrows. The tip is magnetised along the external field direction, thus opposing the skyrmions core magnetisation