Fig. 6

Magnetic force microscopy (MFM) probe-induced collapse of domains into individual skyrmions. a–h Sequence of MFM images illustrating conversion of domains into skyrmions via MFM in Pt/CoFeB/MgO multilayer under an applied perpendicular field \({H}_{{\rm{z}}}\) = 57 mT. All images are acquired in single pass MFM mode at a lift height \(\Delta z\) = 145 nm. A topography scan with a line spacing \(\delta\) \(\sim\) 40 nm is performed between each image (not shown), with the slow scan axis direction as indicated by the arrows. Symbols D\({}_{1}\) and D\({}_{2}\) mark two stripe domains which convert into skyrmions S\({}_{1}\) and S\({}_{2}\), respectively, upon successive topography scans, as explained in the text. In all images the tip is magnetised along the external field direction, thus opposing the skyrmions core magnetisation