One Dimensional Modulation of Electronic States in Bilayer Graphene

Recent advances in van der Waals assemblies have enabled high quality and performance of two-dimensional materials devices, demonstrating emergent condensed matter phenomena. The electronic states of these materials can be manipulated by imposing artificially designed potentials through an external electric field. We fabricated a one-dimensional periodic top-gate on h-BN encapsulated bilayer graphene by state-of-the-art electron beam lithography. Through combination of the grating-like top-gate potential and local graphite back-gate, the imposed electric potential strength can be well controlled and modulate the electronic properties of bilayer graphene. We observed signatures of superlattice modulation on both the first and secondary charge neutral points in the longitudinal resistance measurement at zero magnetic field. The change of modulation pattern with weak magnetic field is also studied. Our modulated bilayer graphene may hold promise for the realization of electron distributed Bragg reflector (DBR) in the future application of electron optics.