Twisted Bogoliubov quasiparticles in the superconducting NbSe₂ monolayer on graphene

The superconducting properties of layered materials can be controlled by thinning, stacking, and twisting, demanding investigation of electronic states by spectroscopic means at the nanometer scale. Here, we reveal the spatial variations of the electronic states in heterostructures of the superconducting monolayer NbSe₂/graphene using spectroscopic-imaging scanning tunneling microscopy. The NbSe₂ monolayer grown by molecular beam epitaxy is naturally twisted with respect to the graphene substrate and exhibits interference patterns of Bogoliubov quasiparticles twisted with respect to the NbSe₂ and graphene lattices. We find that the twisted interference patterns originate from a sextet of regions in momentum space where the Fermi surfaces of NbSe₂ and graphene overlap. The Fermi surface overlap is sensitive to the twist angle, providing a knob to tune superconductivity.