Using a self-consistent Hartree-Fock theory, we show that the recently observed ferromagnetism in twisted bilayer WSe2 [Nat. Commun. 16, 1959 (2025)] can be understood as a Stoner-like instability of interaction-renormalized moir\'e bands. We quantitatively reproduce the observed Lifshitz transition as function of hole filling and applied electric field that marks the boundary between layer-hybridized and layer-polarized regimes. The former supports a ferromagnetic valley-polarized ground state below half-filling, developing a topological charge gap at half-filling for smaller twist angles. At larger twist angles, the system hosts a gapped triangular N\'eel antiferromagnet. On the other hand, the layer-polarized regime supports a stripe antiferromagnet below half-filling and a wing-shaped multiferroic ground state above half-filling. We map the evolution of these states as a function of filling factor, electric field, twist angle, and interaction strength. Our results demonstrate that long-range exchange in a symmetry-unbroken parent state with strongly renormalized moir\'e bands provides a broadly applicable framework to understand itinerant magnetism in moir\'e TMDs.
@article{arxiv.2503.09689,
title = {Itinerant Magnetism in Twisted Bilayer WSe$_2$ and MoTe$_2$},
author = {Liangtao Peng and Christophe De Beule and Yiyang Lai and Du Li and Li Yang and E. J. Mele and Shaffique Adam},
journal= {arXiv preprint arXiv:2503.09689},
year = {2025}
}