Graphene is the wonder material: it is strong, it has ultra-high mobility, and it has a special band structure, which makes it interesting for fundamental research. The properties of graphene can also be engineered by combining it with other 2D materials using van der Waals stacking – like putting bricks of LEGO on top of each other. There are quite many building blocks available now: semiconductors, superconductor, magnets and materials with larger spin-orbit interaction. The combination of these can lead to novel phases from gate tunable magnets to topological superconductors.

If two superconductors are connected with a short normal or insulating segments, also called Josephson junction, a dissipationless supercurrent can flow between them. This current carries information on the scattering strength, the presence of spin orbit or exchange interactions or topological nature of the normal region. Therefore by attaching the graphene heterostructures to superconducting electrodes a sensitive tool is obtained to study the properties of the system.

During the diploma work the candidate will be involved in engineering Josephson junctions from graphene based heterostructures. The candidate will use electron-beam lithography to realize the nano-circuits and will study Fraunhofer and current phase relation measurements on these circuits at ultra-low temperatures. The work is done in close collaboration with several European universities.