- By:
- Tiukalova, Elizaveta ; Olunloyo, Olugbenga; Xiao, Kai ; Yan, Jiaqiang ; Lupini, Andrew R; Chi, Miaofang
- Journal Name:
- Nano Letters
- Page Number:
- 7485-7492
- Volume:
- 26
- Issue Number:
- 23
- Publication Date:
- June 24, 2026
- View DOI Listing:
- https://doi.org/10.1021/acs.nanolett.5c05483
Abstract
van der Waals twisted bilayers of transition-metal dichalcogenides exhibit diverse excitonic phenomena arising from moirĂ© superlattices and lattice reconstruction. While interlayer strain and relaxation reshape their electronic bands, their nanoscale influence on the excitonic fine structure remains poorly understood. Here, we study the interplay between spin–orbit coupling (SOC) and the moirĂ© lattice by probing excitons in H-type twisted (∼8-layer Ă— 8-layer) MoTe2 using atomic-resolution scanning transmission electron microscopy (STEM) combined with monochromated electron energy loss spectroscopy (EELS) at cryogenic temperature. Spatially resolved spectra reveal moirĂ©-site-dependent variations in excitonic absorption, including modulation of the XB exciton across the moirĂ© unit cell. We find that SOC in MoTe2 increases with the twist angle within the studied range (2–4.5°), with the largest value observed at 4°. These findings establish the twist angle as a tunable parameter for SOC via moirĂ© engineering and link local structural relaxation to excitonic fine structure in twisted MoTe2.
