Magnetically confined graphene quantum dots

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This project is based on our recent realization of smoothly confined graphene quantum dots using Landau level gaps in combination with local electric fields. These dots appear to be much more controlled in terms of filling sequences by orbital, valley and spin levels than lithographic graphene quantum dots, which typically suffer from edge disorder. In particular, robust orbital and valley splittings are identified, in excellent agreement with detailed tight-binding calculations. Changing the lateral position of the quantum dot by sub-nm displacements with respect to the superstructure of graphene on hexagonal boron nitride additionally allows for accurate tuning of the different energy scales with variations in the 10 meV range. These remarkable results are so far restricted to the tip of a scanning tunneling microscope, which is used simultaneously to charge and to probe the quantum dot. This project aims to- develop multiple contact experiments including back gates and additional side contacts in order to provide tuning and precise control of this novel type of quantum dot,- perform dynamic measurements of the quantum dot electrons down to the sub-ns time scale targeting the exploitation of the theoretically predicted favorable relaxation and coherence properties of graphene quantum dots.- develop a comprehensive theoretical model to understand the dot dynamics at different time and length scales.