Quantum magnetotransport in bilayer MoS2: Influence of perpendicular electric field

We first derive the energy dispersion of bilayer MoS2 in the presence of a perpendicular electric field E-z. We show that the band gap and layer splitting can be controlled by the field E-z. Away from the k point, the intrinsic spin-orbit coupling splitting increases in the conduction band but is weakly affected in the valence band. We then analyze the band structure in the presence of a perpendicular magnetic field B and the field E-z, including spin and valley Zeeman terms, and evaluate the Hall and longitudinal conductivities. We discuss the numerical results as functions of the fields B and E-z for finite temperatures. The field B gives rise to a significant spin splitting in the conduction band, to a beating in the Shubnikov-de Haas (SdH) oscillations when it is weak, and to their splitting when it is strong. The Zeeman terms and E-z suppress the beating and change the positions of the beating nodes of the SdH oscillations at low B fields and enhance their splitting at high B fields. Similar beating patterns are observed in the spin and valley polarizations at low B fields. Interestingly, a 90% spin polarization and a 100% square-wave-shaped valley polarization are observed at high B fields. The Hall-plateau sequence depends on E-z. These findings may be pertinent to future spintronic and valleytronic devices.