Spin-textured Chern bands in AB-stacked transition metal dichalcogenide bilayers

Yang Zhang; Trithep Devakul; Liang Fu

doi:10.1073/pnas.2112673118

Spin-textured Chern bands in AB-stacked transition metal dichalcogenide bilayers

Proc Natl Acad Sci U S A. 2021 Sep 7;118(36):e2112673118. doi: 10.1073/pnas.2112673118.

Authors

Yang Zhang¹, Trithep Devakul², Liang Fu¹

Affiliations

¹ Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 liangfu@mit.edu yzhang11@mit.edu.
² Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139.

Abstract

While transition-metal dichalcogenide (TMD)-based moiré materials have been shown to host various correlated electronic phenomena, topological states have not been experimentally observed until now [T. Li et al., Quantum anomalous Hall effect from intertwined moiré bands. arXiv [Preprint] (2021). https://arxiv.org/abs/2107.01796 (Accessed 5 July 2021)]. In this work, using first-principle calculations and continuum modeling, we reveal the displacement field-induced topological moiré bands in AB-stacked TMD heterobilayer [Formula: see text]/[Formula: see text] Valley-contrasting Chern bands with nontrivial spin texture are formed from interlayer hybridization between [Formula: see text] and [Formula: see text] bands of nominally opposite spins. Our study establishes a recipe for creating topological bands in AB-stacked TMD bilayers in general, which provides a highly tunable platform for realizing quantum-spin Hall and interaction-induced quantum anomalous Hall effects.

Keywords: continuum model; first principle simulation; moiré superlattice; topological bands.