2024, Optical Microcavity-Induced Moiré Exciton Localization in Twisted WSe2 Homobilayer, Advanced Functional Materials
2024, Optical Microcavity-Induced Moiré Exciton Localization in Twisted WSe2 Homobilayer, Advanced Functional Materials.
Abstract:
Two-dimensional moiré superlattices offer a versatile platform for manipulating quantum materials, exploiting their spatially varying atomic registry to modify electronic structures, resulting in the emergence of flat electronic minibands, enhanced electronic interactions, and the onset of novel quantum phenomena. Despite extensive investigations into moiré excitons within twisted bilayer moiré superlattices, the interplay between moiré superlattices and optical microcavities remains elusive. Here, we investigate a WSe2 homobilayer with a small twist angle positioned on optical microcavities atop a SiO2 (285 nm)/Si substrate. Utilizing low-temperature photoluminescence (PL) spectroscopy, we observe that the twisted homobilayer at the edge of the optical cavity (Edge-THB) exhibits enhanced localization of moiré excitons and a deeper moiré potential. This behavior is attributed to the combined influence of strain induced by the optical microcavity structure on the moiré superlattice and the amplification of the electromagnetic field. Furthermore, we validate the existence of moiré excitons through a comprehensive analysis, encompassing temperature-dependent PL spectra, circularly polarized PL spectra, and Landé g-factor measurements for Edge-THB. Our findings provide valuable insights into the intricate interaction between moiré superlattices and optical microcavities, paving the way for future applications in quantum technologies.
Keywords: Moiré superlattice, Optical microcavity, Twisted homobilayer, Moiré exciton, Linear polarization, g-factor
Link: https://onlinelibrary.wiley.com/doi/epdf/10.1002/adfm.202402493
