English

Emergent Quantum Valley Hall Insulator from Electron Interactions in Transition-Metal Dichalcogenide Heterobilayers

Mesoscale and Nanoscale Physics 2026-04-24 v2

Abstract

We explore the emergence of topological phases in moir\'{e} MoTe2_2/WSe2_2 bilayer, highlighting the crucial role of spin-orbit coupling and Coulomb interactions at two holes per moir\'e unit cell v=2v = 2. Our analysis uncovers robust Quantum Valley Hall Insulating (QVHI) phase and reveals that long-range interactions alone can mediate the interlayer electron tunneling, generating topologically nontrivial bands even in the absence of the corresponding single-particle hopping. Additionally, we show that in the case of band mixing terms originating both from the interaction and single particle physics a competition between topological states realizing ss-wavewave and p±ipp\pm ip-wavewave symmetries can appear. Moreover, within the considered theoretical framework, we present that by introducing a small Zeeman field, one can lift the band inversion in one of the valleys. This leads to a Quantum Anomalous Hall Insulating (QAHI) state with the topological gap opening in a single valley and the other being topologically trivial.

Keywords

Cite

@article{arxiv.2512.02723,
  title  = {Emergent Quantum Valley Hall Insulator from Electron Interactions in Transition-Metal Dichalcogenide Heterobilayers},
  author = {Palash Saha and Michał Zegrodnik},
  journal= {arXiv preprint arXiv:2512.02723},
  year   = {2026}
}