• 文献标题:   Defect-assisted tunneling spectroscopy of electronic band structure in twisted bilayer graphene/hexagonal boron nitride moire superlattices
  • 文献类型:   Article
  • 作  者:   SEO Y, MASUBUCHI S, ONODERA M, MORIYA R, ZHANG YJ, WATANABE K, TANIGUCHI T, MACHIDA T
  • 作者关键词:  
  • 出版物名称:   APPLIED PHYSICS LETTERS
  • ISSN:   0003-6951 EI 1077-3118
  • 通讯作者地址:  
  • 被引频次:   0
  • DOI:   10.1063/5.0084996
  • 出版年:   2022

▎ 摘  要

We report the demonstration of defect-assisted tunneling spectroscopy of the electronic band structure in twisted bilayer graphene (tBLG)/hexagonal boron nitride (h-BN) moire superlattices in which the moire period between the two graphene layers is close to that between the graphene and h-BN layers. We measured both the in-plane and vertical carrier transport in the tBLG/h-BN van der Waals (vdW) tunneling device. The moire periods were determined from the in-plane carrier transport measurements. The observed vertical tunneling transport characteristics indicated that resonant tunneling occurs from the graphite electrode to tBLG through localized defect states in the h-BN tunnel barrier. We observed multiple defect-assisted resonant tunneling trajectories, from which we derived the density of states (DOS) for tBLG. The obtained DOS has broad flatband features, in qualitative agreement with the theoretical predictions. Furthermore, we obtained three types of DOS, suggesting that we probed local band structures corresponding to AA, AB/BA, and domain wall sites in tBLG. Thus, defect-assisted tunneling spectroscopy has potential as a tool to determine the local band structures in twisted 2D vdW materials.& nbsp;Published under an exclusive license by AIP Publishing.