The recent observation of correlated phases in transition metal dichalcogenide moir\'e systems at integer and fractional filling promises new insight into metal-insulator transitions and the unusual states of matter that can emerge near such transitions. Here, we combine real- and momentum-space mapping techniques to study moir\'e superlattice effects in 57.4∘ twisted WSe2 (tWSe2). Our data reveal a split-off flat band that derives from the monolayer Γ states. Using advanced data analysis, we directly quantify the moir\'e potential from our data. We further demonstrate that the global valence band maximum in tWSe2 is close in energy to this flat band but derives from the monolayer K-states which show weaker superlattice effects. These results constrain theoretical models and open the perspective that Γ-valley flat bands might be involved in the correlated physics of twisted WSe2.
@article{arxiv.2211.01192,
title = {Observation of flat $\Gamma$ moir\'e bands in twisted bilayer WSe$_2$},
author = {Gianmarco Gatti and Julia Issing and Louk Rademaker and Florian Margot and Tobias A. de Jong and Sense Jan van der Molen and Jérémie Teyssier and Timur K. Kim and Matthew D. Watson and Cephise Cacho and Pavel Dudin and José Avila and Kumara Cordero Edwards and Patrycja Paruch and Nicolas Ubrig and Ignacio Gutiérrez-Lezama and Alberto Morpurgo and Anna Tamai and Felix Baumberger},
journal= {arXiv preprint arXiv:2211.01192},
year = {2023}
}