Quantum Transport in a Graphene-Superconductor Hybrid Device*

The interplay of superconductivity and the two-dimensional (2D) quantum Hall edge states is of great current interest for both fundamental science and applications. It could be an ideal platform to realize the non-Abelian zero modes, which is crucial for topological quantum computation. Here we fabricated an encapsulated few-layer graphene flake, which is in proximity to s-wave superconducting leads to form a Josephson-junction-like structure. At temperatures down to 20 mK, we have studied the magnetotransport properties of the device in a wide range of magnetic fields (both parallel and perpendicular orientations). In addition, the differential resistance has been measured as well. Experiments show multiple peaks at low fields, which may indicate the existence of Andreev reflections.