Heads-on skyrmion collisions

Abstract Magnetic textures known as skyrmions have captured the attention of the scientific community working on magnetism for a large part of the last decade due to their potential application in novel neuromorphic devices to carry information and perform computational operations [1, 2] . This is due to the ease of manipulation with electrical currents, and the stability of individual skyrmions against interactions with defects or other skyrmions. Now, while there are plenty of reports on skyrmion manipulation using electrical currents, there are very few studies of skyrmion-to-skyrmion interactions (i.e. skyrmion collisions). While there have recently been studies on skyrmion lattices to extract the interaction potential [3, 4] , a more direct approach is to manipulate individual skyrmions directly, which however has been challenging so far. The reason for that is that very few tools allow for manipulating skyrmions individually and with enough precision to cause collisions in a controllable and repeatable way. In here, we show how using magnetic force microscopy (MFM), and the field gradient produced by MFM probes, it is possible to visualize skyrmions, manipulate them, and create skyrmion collisions to study skyrmion-to-skyrmion interactions or investigate the role of pinning at material defects.