One focus of our work is on Josephson junctions realized in different materials (InSb nanoflags, InAs quantum wells, few-layer black phosphorus, and graphene encapsulated in hexagonal Boron Nitride). Besides, Stefan Heun is well known for his work in the quantum Hall regime, where he recently obtained a patent for a programmable resistance standard based on a cascaded quantum Hall bisector.
The second focus of our activity makes use of scanning tunneling microscopy for the study of graphene for hydrogen storage. We have been very active in the investigation of physisorption and chemisorption of both molecular and atomic hydrogen in graphene. Recent highlights include the development of a three-dimensional graphene structure for hydrogen storage.
Finally, funded by an ERC grant, we have studied few-layer black phosphorus, a newly re-discovered van der Waals material with exciting properties (high mobility and strong anisotropy in the electronic properties). We were the first to demonstrate a planar Josephson junction from a van der Waals material beyond graphene.