Confined-state physics and signs of fermionization of moiré excitons in WSe₂/MoSe₂ heterobilayers

Abstract

We revisit and extend the standard bosonic interpretation of interlayer excitons in the moiré potential of twisted heterostructures of transition-metal dichalcogenides. In our experiments, we probe a high quality MoSe2/WSe2 van der Waals bilayer heterostructure via density-dependent photoluminescence spectroscopy and reveal strongly developed, unconventional spectral shifts of the emergent moiré exciton resonances. The observation of saturating blueshifts of successive exciton resonances allow us to explain their physics in terms of a model utilizing fermionic saturable absorbers. This approach is strongly inspired by established quantum-dot models, which underlines the close analogy of interlayer excitons trapped in pockets of the moiré potential, and quantum emitters with discrete eigenstates.

Second Harmonic Generation Control in 2D Layered Materials: Status and Outlook

“…Herein, we propose a combination scheme of synergistic regulation SHG on 2DLMs, which includes the following three types, but not limited to. 1) Benefiting from to their weak interlayer vdW interactions, 2DLMs can be artificially stacked at tailored interlayer twist angles to form Moiré superlattices, [ 79,80,403,404 ] which have emerged as an excellent platform for studying the novel quantum properties of 2DLMs. Twisted stacking of 2DLMs with moiré superlattices features twist angle‐dependent crystal symmetry and enables the exploration of special moiré excitons resonances in artificial twisted homotrilayers and heterobilayers in artificial twisted homo‐ and heterostructures ( Figure a).…”