Fig. 1: Mechanism of enhanced e-e interaction effects by virtue of charge transfer in graphene-insulator heterostructure.
From: Synergistic correlated states and nontrivial topology in coupled graphene-insulator heterostructures
a Cartoon illustration of a monolayer graphene (black balls with sticks) supported by an insulating substrate (green platform) with long-wavelength charge order (blue dots), with an interlayer distance d. b Schematic of charge transfer in a band-aligned graphene-insulator heterostructure and its effects on the Dirac dispersion. The dashed line marks the Fermi energy EF. c Blue lines show the non-interacting band structure of graphene coupled to a superlattice Coulomb potential with rectangular symmetry. The anisotropy parameter is r = 1.2 and the superlattice constant Lx = Ls = 600 Ă…. The red dashed lines represent the non-interacting Dirac cones in free-standing graphene. The inset marks the high-symmetry points in the superlattice Brillouin zone. d The calculated effective fine structure constant α as a function of Ls and dielectric constant ϵr, where the dashed line marks the critical value αc ≈ 0.92.
