• 文献标题:   High-Quality Multiterminal Suspended Graphene Devices
  • 文献类型:   Article
  • 作  者:   KI DK, MORPURGO AF
  • 作者关键词:   multiterminal suspended graphene, ballistic transport, negative resistance, graphene bilayer, quantum hall effect
  • 出版物名称:   NANO LETTERS
  • ISSN:   1530-6984 EI 1530-6992
  • 通讯作者地址:   Univ Geneva
  • 被引频次:   14
  • DOI:   10.1021/nl402462q
  • 出版年:   2013

▎ 摘  要

We introduce a new scheme to realize suspended, multiterminal graphene structures that can be current annealed successfully to obtain uniform, very high quality devices. A key aspect is that the bulky metallic contacts are not connected directly to the part of graphene probed by transport measurements, but only through etched constriction, which prevents the contacts from acting invasively. The device high quality and uniformity is demonstrated by a reproducibly narrow (delta n similar to 10(9) cm(-2)) resistance peak around charge neutrality, by carrier mobility values exceeding 10(6) cm(2) V-1 s(-1), by the observation of integer quantum Hall plateaus starting at 30 mT and of symmetry broken states at about 200 mT, and by the occurrence of a negative multiterminal resistance directly proving the occurrence of ballistic transport. As these multiterminal devices enable measurements that cannot be done in a simpler two-terminal configuration, we anticipate that their use in future studies of graphene-based systems will be particularly relevant.