Dynamic control of moire potential in twisted WS2-WSe2 heterostructures

Moire superlattices are formed by a lattice mismatch or twist angle in two-dimensional materials, which can generate periodical moire potentials leading to strong changes in the band structure, resulting in new quantum phenomena. However, the experimental engineering of in-situ deformation of moire 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 moire potential in twisted WS2-WSe2 heterostructures at room temperature. Deformation of the twisted heterostructure increases the moire potential, causing a red shift of the moire exciton resonance, and observed the red shift 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 moire potential, providing a promising platform for the development of novel quantum devices.

Automated summary

In this study, a dynamic local deformation of twisted WS2-WSe2 heterostructures was achieved at room temperature using a diamond anvil cell (DAC), enabling in-situ dynamic modulation of moire potential. The deformation of the twisted heterostructure increased the moire potential, causing a red shift of the moire exciton resonance. It also observed a red shift of the intralayer exciton resonance and a blue shift of the interlayer excitons of twisted WS2-WSe2 heterostructures.