Fractal Quantum Transport on MoS2 Superlattices: a System with Tunable Symmetry

Electron doping is an excellent tuning knob to explore different phases of matter in two-dimensional (2D) materials. For example, tuning the Fermi level at a van Hove singularity in twisted bilayer graphene can enhance electron-electron interactions and induce a diverse range of correlated phases. Here, using a single-particle picture, we study the electronic reconstruction of the band edges of a 2D semiconductor, monolayer MoS2, on a hexagonal moire potential induced by another MoS2 monolayer. We find that such system transitions from a honeycomb to a hexagonal symmetry when the Fermi level is tuned from the conduction to the valence side. We also study the system under magnetic fields, and construct the Hofstadter's butterfly in the electron- and hole-doped side. Our findings are confirmed by simulating the conductance across a large-scale two-terminal device. We conclude that this duality is a general property that MoS2 and other transition-metal-dichalcogenides exhibit under non-symmetric superlattice potentials.
Comment: 13 pages, 6 figures