Valley Zeeman effect and spin-valley polarized conductance in monolayer MoS2 in a perpendicular magnetic field

We study the effect of a perpendicular magnetic field on the electronic structure and charge transport of a monolayer MoS2 nanoribbon at zero temperature. We particularly explore the induced valley Zeeman effect through the coupling between the magnetic field B and the orbital magnetic moment. We show that the effective two-band Hamiltonian provides a mismatch between the valley Zeeman coupling in the conduction and valence bands due to the effective mass asymmetry and it is proportional to B2 similar to the diamagnetic shift of exciton binding energies. However, the dominant term which evolves with B linearly, originates from the multiorbital and multiband structures of the system. Besides, we investigate the transport properties of the system by calculating the spin-valley resolved conductance and show that, in a low-hole doped case, the transport channels at the edges are chiral for one of the spin components. This leads to a localization of the nonchiral spin component in the presence of disorder and thus provides a spin-valley polarized transport induced by disorder.