The electronic thickness of graphene.

ABSTRACT: When two dimensional crystals are atomically close, their finite thickness becomes relevant. Using transport measurements, we investigate the electrostatics of two graphene layers, twisted by θ = 22° such that the layers are decoupled by the huge momentum mismatch between the K and K' points of the two layers. We observe a splitting of the zero-density lines of the two layers with increasing interlayer energy difference. This splitting is given by the ratio of single-layer quantum capacitance over interlayer capacitance C _m and is therefore suited to extract C _m. We explain the large observed value of C _m by considering the finite dielectric thickness d _g of each graphene layer and determine d _g ≈ 2.6

SUBMITTER: Rickhaus P 

PROVIDER: S-EPMC7069711 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature