  Kagome lattices have an inherent two-dimensional nature. Despite previous
realizations in the monolayer limit, their abilities to drive emergent
electronic states such as correlated insulators have remained unobserved. Here,
we report the experimental realization of a new structural phase of monolayer
Mo33Te56, characterized by its virtually global uniformity as a mirror-twin
boundary loop superlattice embedded in an H-MoTe2 monolayer. Through a
combination of scanning tunnelling microscopy (STM) and theoretical
calculations, we unveil a kagome geometry along with multiple associated sets
of kagome flat bands. Crucially, the partial filling of these kagome bands
induces ferromagnetism as revealed by spin-polarized STM, and leads to a
correlated insulating state exhibiting a hard gap as large as 15 meV. Our
findings represent a major advance in kagome materials, offering a framework
with clearer band structures and more intrinsic two-dimensional properties for
exploring flat-band physics.
