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Søren Ulstrup

Direct observation of minibands in a twisted graphene/WS2 bilayer

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DOI

  • Søren Ulstrup
  • Roland J. Koch, Lawrence Berkeley National Laboratory
  • ,
  • Simranjeet Singh, Carnegie Mellon University
  • ,
  • Kathleen M. McCreary, Naval Research Laboratory
  • ,
  • Berend T. Jonker, Naval Research Laboratory
  • ,
  • Jeremy T. Robinson, Naval Research Laboratory
  • ,
  • Chris Jozwiak, Lawrence Berkeley National Laboratory
  • ,
  • Eli Rotenberg, Lawrence Berkeley National Laboratory
  • ,
  • Aaron Bostwick, Lawrence Berkeley National Laboratory
  • ,
  • Jyoti Katoch, Carnegie Mellon University
  • ,
  • Jill A. Miwa

Stacking two-dimensional (2D) van der Waals materials with different interlayer atomic registry in a heterobilayer causes the formation of a long-range periodic superlattice that may bestow the heterostructure with properties such as new quantum fractal states or superconductivity. Recent optical measurements of transition metal dichalcogenide (TMD) heterobilayers have revealed the presence of hybridized interlayer electron-hole pair excitations at energies defined by the superlattice potential. The corresponding quasiparticle band structures, so-called minibands, have remained elusive, and no such features have been reported for heterobilayers composed of a TMD and another type of 2D material. We introduce a new x-ray capillary technology for performing microfocused angle-resolved photoemission spectroscopy with a spatial resolution of ~1 μm, and directly observe minibands at certain twist angles in mini Brillouin zones (mBZs). We discuss their origin in terms of initial and final state effects by analyzing their dispersion in distinct mBZs.

Original languageEnglish
Article numbereaay6104
JournalScience Advances
Volume6
Issue14
Number of pages7
ISSN2375-2548
DOIs
Publication statusPublished - 2020

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