Stabilization of the skyrmion in a hybrid magnetic-superconducting nanostucture

Stabilizing magnetic skyrmions typically requires a Dzyaloshinskii–Moriya interaction or competing interactions that produce magnetic frustration. An alternative route relies on external fields. In conventional magnetic materials, spatially inhomogeneous magnetic fields—such as demagnetizing or Oersted fields—can stabilize skyrmions. Here, we propose using a superconducting nanoring to locally control and tune the magnetic field in an adjacent ferromagnetic layer. The field generated by a persistent supercurrent stabilizes a Néel skyrmion. We analyze the stabilization conditions in ferromagnetic layers with perpendicular magnetic anisotropy as functions of nanoring size and induced supercurrent. We show that skyrmion stability requires the supercurrent to exceed a critical threshold. Consistent results are presented from analytical modeling and micromagnetic simulations for thin Co and Ga:YIG films.