  Vortex pinning in a type-II superconducting Pb film covering a Co/Pt
multilayer with perpendicular magnetic anisotropy is investigated. Different
stable magnetic domain patterns like band and bubble domains can be created in
the Co/Pt multilayer, clearly influencing the vortex pinning in the
superconducting Pb layer. Most effective pinning is observed for the bubble
domain state. We demonstrate that the pinning properties of the
superconductor/ferromagnet bilayer can be controlled by tuning the size,
density and magnetization direction of the bubbles.
