High Temperature Kinetic Magnetism in Triangular Lattices

This talk will review kinetic magnetism for the Fermi-Hubbard models in triangular type lattices, including four- and six-legged triangular cylinders and a full two-dimensional triangular lattice. Focus will be on the regime of strong interactions, t<<U, and filling factors around one electron per site. For temperatures well above the hopping strength, the Curie-Weiss form of the magnetic susceptibility suggests effective antiferromagnetic correlations for systems that are hole doped with respect to ν=1, and ferromagnetic correlations for systems with electron dopings. It will be shown that these correlations arise from magnetic polaron dressing of charge carrier propagating in a spin incoherent Mott insulator. Effective interactions corresponding to these correlations can strongly exceed the magnetic super-exchange energy. In the case of hole doping, antiferromagnetic polarons originate from kinetic frustration of individual holes in a triangular lattice. In the case electron doping, Nagaoka type ferromagnetic correlations are induced by propagating doublons. Implications of these findings for experiments with moire TMDC materials and ultracold atoms in optical lattices will be discussed.