2025, Pressure-Enhanced Interlayer Coupling and Hybridized Excitons in Twisted MoS2 Moiré Quasicrystals, Nano Letters.
2025, Pressure-Enhanced Interlayer Coupling and Hybridized Excitons in Twisted MoS2 Moiré Quasicrystals, Nano Letters.
Abstract:
Moiré quasicrystals, characterized by broken translational symmetry, emerge in van der Waals (vdW) bilayers twisted 30°, resulting in unique interlayer coupling. Despite their intriguing properties, the modulation of interlayer interactions and its impact on the electronic and phononic behavior of moiré quasicrystals remain underexplored. Here, we synthesize 30° twisted MoS2 bilayers and employ diamond anvil cell (DAC) to dynamically tune their moiré phonons and excitons. Enhanced interlayer coupling under pressure strengthens the moiré potential, shifting moiré phonon away from pristine Raman modes. Furthermore, the broken translational symmetry in moiré quasicrystals facilitates intervalley coupling via Umklapp scattering, leading to hybridized interlayer excitons. These hybridized excitons induce a non-monotonic shift in the photoluminescence peak under pressure, due to the mixing of intralayer and interlayer exciton states. Our findings offer new insights into the physics of moiré quasicrystals and demonstrate high-pressure modulation as a powerful tool for probing and controlling their physical properties.
Keywords: Moiré quasicrystal, moiré potential, hybridized excitons, high pressure, diamond avail cell, interlayer coupling.
Link: https://pubs.acs.org/doi/full/10.1021/acs.nanolett.5c01274
