  Skyrmions are vortex-like localized magnetic structures that possess an
integer-valued topological index known as the skyrmion number or topological
charge. Skyrmion number determines the topology-related emergent magnetism,
which is highly desirable for advanced storage and computing devices. In order
to achieve device functions, it is necessary to manipulate the skyrmion number
in confined nanostructured geometries using electrical methods. Here, we report
the reliable current-controlled operations for manipulating the skyrmion number
through reversible topological transformations between skyrmion chains and
stripe domains in confined Fe3Sn2 nanostripes. The results of micromagnetic
simulations are successful in numerically reproducing our experiments and
explaining them through the combined effect of current-induced Joule heating
and magnetic hysteresis. These findings hold the potential to advance the
development of topological spintronic devices.
