Magnetotransport in Dual-gated MoS₂ van der Waals Heterostructure

Semiconductor transition metal dichalcogenides (TMDs) have attracted significant interest because of their unique combination of two-dimensional nature, large-band gap and strong spin-orbit interaction. Recent advances in contact engineering have allowed Ohmic contact to n-type [1] and p-type [2] TMDs thus enabling study of quantum transport phenomenon at cryogenic temperature. Combining the n-type contact scheme and MoS₂-Boron Nitride (BN) dual-gated heterostructure, we are able to tune the contact and carrier densities of monolayer MoS₂ independently and measure magnetotransport in the density range of 2-10x10¹² cm^-2. The samples display well-defined Shubnikov-de Haas (SdH) oscillations in high magnetic fields. From the temperature dependence of the SdH oscillation amplitude we determine an electron effective mass of 0.46 m_e for monolayer MoS_2. [1] Cui, X.; Shih, E.-M. et al. Nano Lett. 2017, 17, 4781–4786. [2] Movva, H. et al., ACS Nano 2015, 9, 10402–10.