Figure 1. Ab initio electronic structure of transition-metal dichalcogenide monolayers.

(a) Setup: a circularly polarized pump beam irradiates a monolayer transition-metal dichalcogenide ribbon. (b) Band structure and orbital content for MoS₂ and MoSe₂, as well as WS₂ with spin–orbit coupling, determined from ab initio DFT calculations and downfolding onto localized Wannier orbitals. K and K' are related by time-reversal symmetry. (c) Isosurfaces highlight that the effective Wannier orbitals for WS₂, while localized on W, take into account orbital content extending to the S atoms as well as neighbouring W atoms.