  Crystal geometry can greatly influence the emergent properties of quantum
materials. As an example, the kagome lattice is an ideal platform to study the
rich interplay between topology, magnetism, and electronic correlation. In this
work, combining high-resolution angle-resolved photoemission spectroscopy and
ab-initio calculation, we systematically investigate the electronic structure
of XMn6Sn6 (X = Dy, Tb, Gd, Y) family compounds. We observe the Dirac fermion
and the flat band arising from the magnetic kagome lattice of Mn atoms.
Interestingly, the flat band locates in the same energy region in all compounds
studied, regardless of their different magnetic ground states and 4f electronic
configurations. These observations suggest a robust Mn magnetic kagome lattice
across the XMn6Sn6 family, thus providing an ideal platform for the search and
investigation on new emergent phenomena in magnetic topological materials.
