• 文献标题:   Imaging the flow of holes from a collimating contact in graphene
  • 文献类型:   Article
  • 作  者:   BHANDARI S, KREIDEL M, KELSER A, LEE GH, WATANABE K, TANIGUCHI T, KIM P, WESTERVELT RM
  • 作者关键词:   graphene, transport phenomena, scanning technique, scanningprobe microscopy, ballistic transport
  • 出版物名称:   SEMICONDUCTOR SCIENCE TECHNOLOGY
  • ISSN:   0268-1242 EI 1361-6641
  • 通讯作者地址:   Harvard Univ
  • 被引频次:   0
  • DOI:   10.1088/1361-6641/aba08d
  • 出版年:   2020

▎ 摘  要

A beam of holes formed in graphene by a collimating contact is imaged using a liquid-He cooled scanning probe microscope (SPM). The mean free path of holes is greater than the device dimensions. A zigzag shaped pattern on both sides of the collimating contact absorbs holes that enter at large angles. The image charge beneath the SPM tip defects holes, and the pattern of flow is imaged by displaying the change in conductance between contacts on opposite sides, as the tip is raster scanned across the sample. Collimation is confirmed by bending hole trajectories away from the receiving contact with an applied magnetic field. The SPM images agree well with ray-tracing simulations.