Magnetic properties of materials ranging from conventional ferromagnetic metals to strongly correlated materials such as cuprates originate from Coulomb exchange interactions. The existence of alternate mechanisms for magnetism that could naturally facilitate electrical control have been discussed theoretically but an experimental demonstration in an extended system has been missing. Here, we investigate MoSe2/WS2 van der Waals heterostructures in the vicinity of Mott insulator states of electrons forming a frustrated triangular lattice and observe direct evidence for magnetic correlations originating from a kinetic mechanism. By directly measuring electronic magnetization through the strength of the polarization-selective attractive polaron resonance, we find that when the Mott state is electron doped the system exhibits ferromagnetic correlations in agreement with the Nagaoka mechanism.
@article{arxiv.2305.02150,
title = {Kinetic Magnetism in Triangular Moir\'e Materials},
author = {Livio Ciorciaro and Tomasz Smolenski and Ivan Morera and Natasha Kiper and Sarah Hiestand and Martin Kroner and Yang Zhang and Kenji Watanabe and Takashi Taniguchi and Eugene Demler and Atac Imamoglu},
journal= {arXiv preprint arXiv:2305.02150},
year = {2023}
}