Having succeeded in recording the trace of the vortices, the researchers tried to print other sources of magnetic field in the ferromagnetic layer, notably a magnetic structure (NdFeB) composed of squares with sides of 100 µm, alternatively magnetized in opposite directions. When this vary particular “chessboard” is placed in direct contact with the superconductor, it can clearly be seen that the magnetic field is printed in the ferromagnetic layer that covers the superconductor.  

“From now on”, continues Jérémy Brisbois, “the impression of the chessboard left in the magnetic layer can be used to influence the movement of vortices in the superconductor. The advantage of this technique as opposed to drilling holes in the material is that our chessboard is easy to handle: we can imagine a multitude of different geometries and they can easily be changed. One sample is sufficient to test everything: we keep the trace, we erase, and we start again, exactly like a child with their magic drawing board”! This flexibility enables us to make a giant leap forward with regard to the study of vortices and their behavior as well as controlling their movement because it allows the experimenters to easily master the maneuver. It is no longer a case of just looking, but also to guide the vortices in accordance with the aim of the research.