Flat bands in twisted transition metal dichalcogenide bilayers

The electronic properties of transition metal dichalcogenide (TMD) bilayers vary according to the local atomic structure [1]. In minimally twisted bilayers, there is significant atomic reconstruction away from the rigid moiré pattern [2]. We present the results of density functional theory (DFT) calculations that model the electronic properties of MoSe₂/WSe₂ bilayers with a small twist away from commensurate 180-degree stacking. We present band structures and local densities of states that exhibit flat bands in the gap near the band edges.
[1] M. Phillips and C. S. Hellberg, arXiv:1909.02495
[2] S. Carr, et al, Phys. Rev. B 98, 224102