Out-of-Plane Dielectric Susceptibility of Graphene in Twistronic and Bernal Bilayers

Abstract

We describe how the out-of-plane dielectric polarizability of monolayer graphene influences the electrostatics of bilayer graphene-both Bernal (BLG) and twisted (tBLG). We compare the polarizability value computed using density functional theory with the output from previously published experimental data on the electrostatically controlled interlayer asymmetry potential in BLG and data on the on-layer density distribution in tBLG. We show that monolayers in tBLG are described well by polarizability α_<i>exp</i> = 10.8 ų and effective out-of-plane dielectric susceptibility ϵ_<i>z</i> = 2.5, including their on-layer electron density distribution at zero magnetic field and the interlayer Landau level pinning at quantizing magnetic fields.