Massive Dirac fermions in moire superlattices: A route towards topological flat minibands and correlated topological insulators

We demonstrate a generic mechanism to realize topological flat minibands by confining massive Dirac fermions in a periodic moire potential, which can be achieved in a heterobilayer of transition metal dichalco-genides. We show that the topological phase can be protected by the symmetry of moire potential and survive to arbitrarily large Dirac band gap. We take the MoTe2/WSe2 heterobilayer as an example and find that the topological phase can be driven by a vertical electric field. By projecting the Coulomb interaction onto the topological fat minibands, we identify a correlated Chern insulator at half filling and a quantum valley-spin Hall insulator at full filling which explains the topological states observed in the MoTe2/WSe2 in the experiment. Our work clarifies the importance of Dirac structure for the topological minibands and unveils a general strategy to design topological moire materials.

Automated summary

This research demonstrates a generic mechanism to achieve topological flat minibands by confining massive Dirac fermions in a periodic moiré potential. It clarifies the importance of Dirac structure for the topological minibands and unveils a general strategy to design topological moire materials.