• 文献标题:   Tailoring the Band Structure of Twisted Double Bilayer Graphene with Pressure
  • 文献类型:   Article
  • 作  者:   SZENTPETERI B, RICKHAUS P, DE VRIES FK, MARFFY A, FULOP B, TOVARI E, WATANABE K, TANIGUCHI T, KORMANYOS A, CSONKA S, MAKK P
  • 作者关键词:   twisted double bilayer graphene, superlattice, pressure, band structure, transport measurement, continuum modeling
  • 出版物名称:   NANO LETTERS
  • ISSN:   1530-6984 EI 1530-6992
  • 通讯作者地址:  
  • 被引频次:   15
  • DOI:   10.1021/acs.nanolett.1c03066 EA OCT 2021
  • 出版年:   2021

▎ 摘  要

Twisted two-dimensional structures open new possibilities in band structure engineering. At magic twist angles, flat bands emerge, which gave a new drive to the field of strongly correlated physics. In twisted double bilayer graphene dual gating allows changing of the Fermi level and hence the electron density and also allows tuning of the interlayer potential, giving further control over band gaps. Here, we demonstrate that by application of hydrostatic pressure, an additional control of the band structure becomes possible due to the change of tunnel couplings between the layers. We find that the flat bands and the gaps separating them can be drastically changed by pressures up to 2 GPa, in good agreement with our theoretical simulations. Furthermore, our measurements suggest that in finite magnetic field due to pressure a topologically nontrivial band gap opens at the charge neutrality point at zero displacement field.