Electron Transport in Dual-gated Three-layer MoS2
M. Masseroni1, T. Davatz1, R. Pisoni1, F. K. de Vries1, P. Rickhaus1, V. Fal’ko2, T. Ihn1 and K. Ensslin1
1. Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland
2. National Graphene Institute, University of Manchester, Booth St. E. Manchester M13 9PL, United Kingdom
We investigate the conduction band of a dual-gated three layer MoS2 by means of magnetotransport experiments. The overall carrier density is tuned by both top and bottom gates. By applying an asymmetric gate voltage configuration, electrons accumulate in the layer closest to the positively biased electrode, and the three-layer MoS2 behaves electronically like a monolayer. The situation where a positive voltage is applied to both gates leads to the occupation of all three layers. Shubnikov-de Haas oscillations originating from several bands are separately attributed to carrier densities in the top and bottom layers. We find a two-fold Landau level degeneracy for each band, suggesting that the minima of the conduction band lie at the K points of the first Brillouin zone, in contrast to band structure calculations, which report minima at the Q points. Even though the inter-layer tunnel coupling seems to leave the low energy conduction band unaffected, we
observe scattering between the outermost layers, while the middle layer remains decoupled due to the inverted
spin/valley symmetry.[1]
[1] Masseroni Michele, Davatz Tim, Pisoni Riccardo, de Vries Folkert K., Rickhaus Peter, Taniguchi Takashi, Watanabe Kenji, Fal’ko Vladimir, Ihn Thomas, and Ensslin Klaus, Electron transport in dual-gated threelayer MoS2, Phys. Rev. Research 3, 023047 (2021).