Investigating the electronic structure of bilayer graphene/RuCl₃heterostructure

Stacking two-dimensional(2D) materials to form Van der Waals (vdW) heterostructures provides an unprecedented ability to tune electronic structures and engineer novel interfaces. Among these materials, α-RuCl₃ has recently attracted significant attention as a Mott insulator, and interfacing with graphene induces massive charge transfer from the Graphene layer to itself, significantly modifying graphene’s electronic properties. By employing angle-resolved photoemission spectroscopy with nanoscale spatial resolution (nanoARPES), we study the electronic structure of bilayer graphene(BG) when interfaced with α-RuCl₃ and hexagonal boron nitride(hBN) and further tune the Fermi level of the heterostructure via potassium atom deposition. Our experiment reveals the presence of semi-metallic states at Dirac point in BG/RuCl₃ /hBN as a result of AA+AB stacking and gap (Δ~0.4 eV) opens up in BG/hBN due to sublattice symmetry breaking.