Minibands in Short-Wavelength Graphene/WSe<sub>2</sub> Moiré Superlattices

ORAL

Abstract

Moiré superlattices comprised of stacked two-dimensional materials present a versatile platform for engineering and investigating new emergent quantum states of matter. At present, the vast majority of investigated systems have long moiré wavelengths, but investigating these effects at shorter, incommensurate wavelengths remains a challenge. How can the electronic features of the superlattice be described when the continuum limit is no longer applicable? Do minibands still form in such short wavelength systems? We demonstrate that a relatively simple tight-binding model treating the effect of the moiré superlattice as an imposed, external potential can accurately describe the electronic structure of new short-wavelength minibands, and that our findings are supported by ab initio calculations. We present our results in tandem with angle-resolved photoemission spectroscopy (ARPES) measurements studying a short moiré wavelength of 0.5 nm for twisted graphene/WSe2, in which distinct minibands formed by the moiré potential are observed despite the sub-nanometer moiré wavelength. 

*This work was supported through the National Science Foundation [Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials (PARADIM)] under Cooperative Agreement Number DMR-1539918, NSF DMR-1709255, and the Air Force Office of Scientific Research Grant Number FA9550-15-1-0474. This research used resources of the Advanced Light Source, which is a DOE Office of Science User Facility under contract no. DE-AC02-05CH11231. S.X. acknowledges support from a Kavli Postdoctoral Fellowship. B.D.F. acknowledges support from the NSF Graduate Research Fellowship under Grant Number DGE-1650441. This work made use of the Cornell Center for Materials Research Shared Facilities, which are supported through the NSF MRSEC programme (DMR-1719875).

Publication: https://arxiv.org/abs/2010.07806

Presenters

  • Eli Gerber

    • Cornell University

Authors

  • Eli Gerber

    • Cornell University
  • Saien Xie

    • Cornell University
  • Brendan D Faeth

    • Cornell University
  • Yanhao Tang

    • Cornell University
  • Lizhong Li

    • Cornell University
  • Christopher T Parzyck

    • Cornell University
  • Debanjan Chowdhury

    • Cornell University
  • Yahui Zhang

    • Harvard University
  • Christopher Jozwiak

    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Lab
    • E. O. Lawrence Berkeley National Laboratory
    • lawrence berkeley lab
    • Advanced Light Source, Lawrence Berkeley National Laboratory
  • Aaron Bostwick

    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Lab
    • E. O. Lawrence Berkeley National Laboratory
    • lawrence berkeley lab
    • Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley
  • Eli Rotenberg

    • Lawrence Berkeley National Laboratory
  • Jie Shan

    • Cornell University
    • Cornell
  • Kin Fai Mak

    • Cornell University
  • Eun-Ah Kim

    • Cornell University
  • Kyle M Shen

    • Cornell University