Superconductivity in the quantum Hall regime.
Combining superconductivity and the quantum Hall (QH) effect is a promising route for creating new types of topological excitations. Despite this potential, signatures of superconductivity in the quantum Hall regime remain scarce, and a superconducting current through a quantum Hall weak link has so far eluded experimental observation. Indeed, contrary to the case of topological insulators, the magnetic field in the QH regime breaks time-reversal symmetry, which is essential for s-wave pairing of conventional superconductors. Nonetheless, we observe a robust supercurrent in the quantum Hall regime, in graphene encapsulated in boron nitride. The electronic quality of these heterostructures results in a robust Landau quantization at low fields, which makes them particularly suitable to engineer QH/superconductor hybrids.I will discuss the role of the superconducting interface, edge states, and Andreev bound states in observation of the Josephson effect through a QH region.