Anisotropic transport in graphene via 1D patterned dielectric superlattices*

Band structure engineering of two-dimensional materials entered the spotlight with the experimental discovery of Hofstadter's butterfly in graphene on hexagonal boron nitride. Recently it became possible to fabricate device structures with features beyond the limitations imposed by the naturally occurring moiré pattern through the use of patterned dielectric superlattices (PDSLs). In these devices, the dielectric between the back gate and the graphene is periodically structured to create a modulated carrier density on the order of tens of nanometers. We report the fabrication and measurement of 1D PDSLs that produce highly anisotropic transport in monolayer graphene. Resistivity measured perpendicular to the 1D superlattice shows the standard Dirac peak while resistivity measured parallel to the 1D superlattice demonstrates additional satellite peaks. Additionally, we observe Weiss oscillations when the cyclotron orbit of carriers is commensurate with the superlattice wavelength. These observations mark a crucial step for the in-situ tunable modification of graphene’s band structure in a highly anisotropic fashion that has applications in ballistic electron optics, van der Waals FETs, and plasmonics.