Magnetic circuit for Abrikosov vortices: Vortex motion in a periodic labyrinth of magnetic T and I-shaped elements under and above a superconducting film*

We report on the comprehensive study of the arrays of magnetic T and I-letter-shaped thin permalloy elements on the Abrikosov vortex dynamics in superconducting niobium films deposited under or above the magnetic pattern. Direct observations of the vortex motion using magneto-optical imaging technique, supported by transport measurements at temperatures close to Tc, show that the TI-elements create a robust magnetic potential for vortices, which can be easily reconfigured with rotating a moderate in-plane field. Such a tunable magnetic potential allowing control of the vortex trajectories can be a useful tool for manipulating vortices in fluxonic devices, and have a potential for implementing vortex braiding in quantum Majorana operations.