Large conduction band and Fermi velocity spin splitting due to Coulomb interactions in single-layer MoS2

We study the effect of Coulomb interactions on the low-energy band structure of single-layer transition metal dichalcogenide semiconductors using an effective low-energy model. We show how a large conduction band spin splitting and a spin dependent Fermi velocity are generated in MoS2, as a consequence of the difference between the gaps of the two spin projections induced by the spin-orbit interaction. The conduction band and Fermi velocity spin splitting found are in agreement with the optical absorption energies of the excitonic peaks A, B measured in the experiments.