Visualizing Atomic-Scale Negative Differential Resistance in Bilayer Graphene

Abstract

We investigate the atomic-scale tunneling characteristics of bilayer graphene on silicon carbide using the scanning tunneling microscopy. The high-resolution tunneling spectroscopy reveals an unexpected negative differential resistance (NDR) at the Dirac energy, which spatially varies within the single unit cell of bilayer graphene. The origin of NDR is explained by two near-gap van Hove singularities emerging in the electronic spectrum of bilayer graphene under a transverse electric field, which are strongly localized on two sublattices in different layers. Furthermore, defects near the tunneling contact are found to strongly impact on NDR through the electron interference. Our result provides an atomic-level understanding of quantum tunneling in bilayer graphene, and constitutes a useful step towards graphene-based tunneling devices.

6 pages, 5 figures, accepted for publication in Physical Review Letters

References in corpus (10)

• Field-effect tunneling transistor based on vertical graphene heterostructures
• Atomically thin boron nitride: a tunnelling barrier for graphene devices
• Electronic states and Landau levels in graphene stacks
• Ab Initio Theory of Gate Induced Gaps in Graphene Bilayers
• Controlling Energy Gap of Bilayer Graphene by Strain
• Quasiparticle Chirality in Epitaxial Graphene Probed at the Nanometer Scale
• Charge transfer between epitaxial graphene and silicon carbide
• Tuning Negative Differential Resistance in a Molecular Film
• Engineering Negative Differential Conductance with the Cu(111) Surface State
• Effect of impurities in high-symmetry lattice positions on the local density of states and conductivity of graphene

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• Magnetic-field-controlled negative differential conductance in graphene npn junction resonators
• Origami-controlled strain engineering of tunable flat bands and correlated states in folded graphene
• Nanoscale Probing of Broken-Symmetry States in Graphene Induced by Individual Atomic Impurities
• Current flow in biased bilayer graphene: the role of sublattices
• Spectroscopic Characterization of Landau Level Splitting and the Intermediate v = 0 Phase in Bilayer Graphene
• Gap state charge induced spin-dependent negative differential resistance in tunnel junctions
• Atomic-Scale Tailoring of Chemisorbed Atomic Oxygen on Epitaxial Graphene for Graphene-Based Electronic Devices
• Probing the features of electron dispersion by tunneling between slightly twisted bilayer graphene sheets
• Emergence of metallic surface states and negative differential conductance in thin $\beta$-FeSi${}_2$ films on Si(001)