Moir\'e superlattices in twisted van der Waals materials constitute a promising platform for engineering electronic and optical properties. However, a major obstacle to fully understanding these systems and harnessing their potential is the limited ability to correlate the local moir\'e structure with optical properties. By using a recently developed scanning electron microscopy technique to image twisted WSe2/WSe2 bilayers, we directly correlate increasing moir\'e periodicity with the emergence of two distinct exciton species. These can be tuned individually through electrostatic gating, and feature different valley coherence properties. Our observations can be understood as resulting from an array of two intralayer exciton species residing in alternating locations in the superlattice, and illuminate the influence of the moir\'e potential on lateral exciton motion. They open up new avenues for controlling exciton arrays in twisted TMDs, with applications in quantum optoelectronics and explorations of novel many body systems.
@article{arxiv.1912.06955,
title = {Moir\'e Excitons Correlated with Superlattice Structure in Twisted WSe$_2$/WSe$_2$ Homobilayers},
author = {Trond I. Andersen and Giovanni Scuri and Andrey Sushko and Kristiaan De Greve and Jiho Sung and You Zhou and Dominik S. Wild and Ryan J. Gelly and Hoseok Heo and Kenji Watanabe and Takashi Taniguchi and Philip Kim and Hongkun Park and Mikhail D. Lukin},
journal= {arXiv preprint arXiv:1912.06955},
year = {2021}
}
Comments
25 pages, 4 figures in main text, 4 figures in supplementary materials