Evolution of the electronic structure of twisted bilayer MoSe2

Abstract

In this work we examine the evolution of the electronic structure in twisted bilayers of $\mathrm{Mo}{\mathrm{Se}}_{2}$, assuming the moir\'e potential to be a small perturbation to the untwisted limit. Its role in modifying the electronic structure is probed by mapping the calculated band structure for the moir\'e cell onto the primitive cell direction which represents the untwisted limit. At large twist angles such as $19.{03}^{\ensuremath{\circ}}$, we find that the moir\'e cell band structure is identical to the primitive cell one in the low-energy window. There are, however, significant deviations for small twist angles such as $3.{48}^{\ensuremath{\circ}}$ which have large patches of high-symmetry regions of AA and ${\mathrm{AB}}^{\ensuremath{'}}$ stackings. These lead to enhanced interlayer hopping interaction strengths in some regions, and hence stronger perturbations leading to subband formation of the highest occupied band, which has a bandwidth of 19 meV and is found to be localized both in real space as well as in momentum space.