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arXiv · 2608.30813

Supermoir\'e Reconstruction and Topological Mosaics in Twisted Trilayer WSe$_2$ and MoTe$_2$

Hai Meng·Yang Xu·Fengcheng Wu
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Abstract

We investigate lattice relaxation and band structures of helical and alternating twisted trilayer WSe$_2$ and MoTe$_2$ using machine-learning force fields and large-scale ab initio calculations. Interference between the two bilayer moir\'e lattices generates a supermoir\'e lattice that, upon relaxation, reconstructs into a few dominant domain types with locally commensurate bilayer moir\'e lattices. Because the systems lack $C_{2z}$ symmetry, domains otherwise related by this symmetry become energetically and topologically distinct, unlike in twisted trilayer graphene. Band structure calculations show that the topmost valence bands originate from the $K$ ($K'$) valleys and carry domain-dependent valley Chern numbers. The resulting supermoir\'e lattice hosts a mosaic of topologically inequivalent domains, offering a platform for exploring correlated and topological physics.

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Hai Meng, Yang Xu, Fengcheng Wu. 2026-08-31. Supermoir\'e Reconstruction and Topological Mosaics in Twisted Trilayer WSe$_2$ and MoTe$_2$. https://arxiv.org/abs/2608.30813

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