To assess prior mean-field claims that the interacting Kane-Mele model hosts a novel z−antiferromagnetic (AFM) Chern insulating phase for a wide range of sub-lattice potentials, we analyze the Kane-Mele-Hubbard model in the presence of a sub-lattice potential using non-perturbative determinant quantum Monte Carlo simulations. We find instead that the true low-temperature state is a quantum spin Hall insulator for intermediate values of the sub-lattice potential λv and large on-site repulsion. Two kinds of magnetic fluctuations are found to compete: z- and xy-AFM. The latter dominates at low temperature leading to a stabilization of the quantum spin Hall state as opposed to z−AFM Chern insulator. Our work is consistent with the robust quantum spin Hall effects which are consistently observed at even-integer fillings over a wide range of parameters in twisted bilayer MoTe2 and WSe2 as well as AB stacked MoTe2/WSe2.
@article{arxiv.2409.07557,
title = {Incipient quantum spin Hall insulator under strong correlations},
author = {Peizhi Mai and Jinchao Zhao and Philip W. Phillips},
journal= {arXiv preprint arXiv:2409.07557},
year = {2025}
}