Realizing the Kondo lattice Model in Electron Doped Heterogeneous TMD Bilayers

Moire potentials in vdW bilayers have been recently extended from graphene to a variety of transition metal dichalcogenides (TMDs). In particular, correlated insulating states were observed in heterogeneous TMD bilayers. On the hole doped side the flat mini-bands are isolated from one another due to large spin-orbit splittings. However, on the electron doped side these splittings tend to be much smaller allowing for a partial population of more than one flat band simultaneously. This opens an interesting path to study the interplay of itinerant and localized electrons in moire superlattices.
We explore the phase diagram of electron doped TMD bilayers. We show that the band structure near the K, K' points, is described by two spin-degenerate parabolic bands with different masses, resulting in nearly overlapping flat bands with different widths. Using a slave-rotor decomposition, we show that for strong enough interaction a Mott state can be stabilized in the flatter of the two bands, while the doping in the wider band is continuously tuned from zero. We also find intermediate states where both bands are in the Mott state. Thus, we propose the possible simulation of a Kondo lattice model and unconventional magnets in moire superlattices based on TMDs.