Visualizing atomic-scale negative differential resistance in bilayer graphene

Keun Su Kim, Tae Hwan Kim, Andrew L. Walter, Thomas Seyller, Han Woong Yeom, Eli Rotenberg, Aaron Bostwick

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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.

Original languageEnglish
Article number036804
JournalPhysical Review Letters
Volume110
Issue number3
DOIs
Publication statusPublished - 2013 Jan 18

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All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Kim, K. S., Kim, T. H., Walter, A. L., Seyller, T., Yeom, H. W., Rotenberg, E., & Bostwick, A. (2013). Visualizing atomic-scale negative differential resistance in bilayer graphene. Physical Review Letters, 110(3), [036804]. https://doi.org/10.1103/PhysRevLett.110.036804