Current-Driven Nonreciprocal Response of Nonequilibrium Skyrmions

Electrical control of spins and their collective textures, such as topologically protected skyrmions, is highly desirable for unlocking their potential in future electronic technologies. Here, we design and fabricate thin films of FeGe and Co₈.₅Zn₈.₅Mn₃, each containing a small central hole comparable in size to individual skyrmions, to investigate how nonuniform electron flow influences skyrmions and drives nonreciprocal skyrmion dynamics. Using in situ real-space imaging, we observe that current crowding around the hole triggers skyrmion nucleation and produces direction-dependent skyrmion motion, in agreement with theoretical models and numerical simulations. Notably, the current-driven nonequilibrium skyrmion reveals a striking manifestation of topological spin textures, offering new opportunities for information processing that leverages skyrmion nonreciprocity, such as in reservoir computing.