2022, Dynamic control of Moiré potential in twisted WS2-WSe2 heterostructures, Nano Research

2022, Dynamic control of Moiré potential in twisted WS₂-WSe₂ heterostructures, Nano Research

Abstract:

Moiré superlattices are formed by a lattice mismatch or twist angle in two-dimensional materials, which can generate periodical moiré potentials leading to strong changes in the band structure, resulting in new quantum phenomena. However, the experimental engineering of in-situ deformation of moiré heterostructures remains deficient. Here, we demonstrate a dynamic local deformation of the twisted heterostructures using a diamond anvil cell (DAC), enabling in-situ dynamic modulation of moiré potential in twisted WS₂-WSe₂ heterostructures at room temperature. Deformation of the twisted heterostructure increases the moiré potential, causing a redshift of the moiré exciton resonance, and observed the redshift of the intralayer exciton resonance up to 16.3 meV (less than 1.1 GPa). The blue shift of the interlayer excitons of twisted WS₂-WSe₂ heterostructures shows an evident transition of the pressure-sensitive exciton, induced by the dominant effect of modifying the band structure on optical properties. Combined with the spectral changes of pressurized Raman, which further demonstrated that the DAC can efficiently regulate the interlayer coupling. Our results offer an effective strategy for in-situ dynamic modulation of moiré potential, providing a promising platform for the development of novel quantum devices.

Keywords: Moiré superlattices, twisted heterostructures, moiré potential, diamond anvil cell(DAC)

Link:https://link.springer.com/article/10.1007/s12274-022-4579-9

Dynamic control of moiré potential in twisted WS2—WSe2 heterostructures.pdf