• 文献标题:   Visualizing Atomic-Scale Negative Differential Resistance in Bilayer Graphene
  • 文献类型:   Article
  • 作  者:   KIM KS, KIM TH, WALTER AL, SEYLLER T, YEOM HW, ROTENBERG E, BOSTWICK A
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW LETTERS
  • ISSN:   0031-9007 EI 1079-7114
  • 通讯作者地址:   EO Lawrence Berkeley Natl Lab
  • 被引频次:   11
  • DOI:   10.1103/PhysRevLett.110.036804
  • 出版年:   2013

▎ 摘  要

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. DOI: 10.1103/PhysRevLett.110.036804