• 文献标题:   Gate-Tunable Two-Dimensional Superlattices in Graphene
  • 文献类型:   Article
  • 作  者:   HUBER R, LIU MH, CHEN SC, DRIENOVSKY M, SANDNER A, WATANABE K, TANIGUCHI T, RICHTER K, WEISS D, EROMS J
  • 作者关键词:   graphene, gatetunable, superlattice, satellite dirac point, hofstadter butterfly
  • 出版物名称:   NANO LETTERS
  • ISSN:   1530-6984 EI 1530-6992
  • 通讯作者地址:   Univ Regensburg
  • 被引频次:   2
  • DOI:   10.1021/acs.nanolett.0c03021
  • 出版年:   2020

▎ 摘  要

We report an efficient technique to induce gatetunable two-dimensional superlattices in graphene by the combined action of a back gate and a few-layer graphene patterned bottom gate complementary to existing methods. The patterned gates in our approach can be easily fabricated and implemented in van der Waals stacking procedures, allowing flexible use of superlattices with arbitrary geometry. In transport measurements on a superlattice with a lattice constant a = 40 nm, well-pronounced satellite Dirac points and signatures of the Hofstadter butterfly including a nonmonotonic quantum Hall response are observed. Furthermore, the experimental results are accurately reproduced in transport simulations and show good agreement with features in the calculated band structure. Overall, we present a comprehensive picture of graphene-based superlattices, featuring a broad range of miniband effects, both in experiment and in theoretical modeling. The presented technique is suitable for studying more advanced geometries which are not accessible by other methods.