Rotational and dilational reconstruction in transition metal dichalcogenide moiré bilayers

Madeline Van Winkle; Isaac M. Craig; Stephen Carr; Medha Dandu; Karen C. Bustillo; Jim Ciston; Colin Ophus; Takashi Taniguchi; Kenji Watanabe; Archana Raja; Sinéad M. Griffin; D. Kwabena Bediako

doi:10.1038/s41467-023-38504-7

Article Rotational and dilational reconstruction in transition metal dichalcogenide moiré bilayers

Madeline Van Winkle ; Isaac M. Craig ; Stephen Carr ; Medha Dandu ; Karen C. Bustillo ; Jim Ciston ; Colin Ophus ; Takashi Taniguchi (National Institute for Materials Science) ; Kenji Watanabe (National Institute for Materials Science) ; Archana Raja ; Sinéad M. Griffin ; D. Kwabena Bediako

Download file (6.48 MB)
Download as zip (5.87 MB)

Collection

Citation

Madeline Van Winkle, Isaac M. Craig, Stephen Carr, Medha Dandu, Karen C. Bustillo, Jim Ciston, Colin Ophus, Takashi Taniguchi, Kenji Watanabe, Archana Raja, Sinéad M. Griffin, D. Kwabena Bediako. Rotational and dilational reconstruction in transition metal dichalcogenide moiré bilayers. Nature Communications. 2023, 14 (1), 2989. https://doi.org/10.1038/s41467-023-38504-7

(BibTeX)

Description:

(abstract)

Lattice reconstruction and corresponding strain accumulation play a key role in determining the electronic band structure of two-dimensional moir ́e super- lattices, including those of transition metal dichalcogenides (TMDs). Imaging experiments of TMD moir ́e systems have so far provided a qualitative under- standing of the end product of this lattice relaxation process in terms of in- terlayer stacking energy, while quantitative models have relied exclusively on theoretical simulations. Here, we use interferometric four-dimensional scanning transmission electron microscopy to quantitatively map the mechanical defor- mations through which reconstruction occurs in small-angle twisted bilayer MoS2 and WSe2/MoS2 heterobilayers with sub-nanometer resolution. We find that lo- cal rotations govern the intrinsic reconstruction process for both parallel- and anti-parallel orientations of twisted homobilayers, while local dilations dominate in heterobilayers with a sufficiently large lattice constant mismatch. Extrinsic uniaxial heterostrain, which introduces a lattice constant difference in twisted homobilayers, leads to further accumulation as well as redistribution of recon- struction strain, offering another route to modify the moir ́e potential landscape.

Rights: