Switching of a target skyrmion by a spin-polarized current

We study the spin-transfer-induced dynamics of a target skyrmion in the free layer of nanopillar structures, in which the polarizer layer has a perpendicular magnetization. By using micromagnetic simulations, it is shown that three distinct modes can be excited. As a consequence of the evolution of the lowest frequency mode, breathing mode, the polarized direction of the skyrmion core can be switched via Bloch point injection and propagation.