Dynamic Tuning of Moiré Excitons in a WSe2/WS2Heterostructure via Mechanical Deformation

Wenyu Zhao, Emma C. Regan, Danqing Wang, Chenhao Jin, Satcher Hsieh, Zhiyuan Wang, Jialu Wang, Zilin Wang, Kentaro Yumigeta, Mark Blei, Kenji Watanabe, Takashi Taniguchi, Sefaattin Tongay, Norman Y. Yao, Feng Wang

Research output: Contribution to journalArticlepeer-review

Abstract

Moiré superlattices in van der Waals (vdW) heterostructures form by stacking atomically thin layers on top of one another with a twist angle or lattice mismatch. The resulting moiré potential leads to a strong modification of the band structure, which can give rise to exotic quantum phenomena ranging from correlated insulators and superconductors to moiré excitons and Wigner crystals. Here, we demonstrate the dynamic tuning of moiré potential in a WSe2/WS2 heterostructure at cryogenic temperature. We utilize the optical fiber tip of a cryogenic scanning near-field optical microscope (SNOM) to locally deform the heterostructure and measure its near-field optical response simultaneously. The deformation of the heterostructure increases the moiré potential, which leads to a red shift of the moiré exciton resonances. We observe the interlayer exciton resonance shifts up to 20 meV, while the intralayer exciton resonances shift up to 17 meV.

Original languageEnglish (US)
Pages (from-to)8910-8916
Number of pages7
JournalNano Letters
Volume21
Issue number20
DOIs
StatePublished - Oct 27 2021

Keywords

  • Cryogenic near-field nanoscopy
  • Moiré exciton
  • Nanoindentation

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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