Fig. 1: Schematic illustration of the on-surface strategy to construct artificial electronic kagome lattices.

a Hexagonal building blocks, with side lengths a and b, self-assemble into halogen-hydrogen bonded organic frameworks (XHOFs) on coinage metal (111) surfaces. The quantum destructive interference, as illustrated by arrows, gives rise to flat bands, with real-space localization within the blue-shadowed triangles. b Schematic drawing of the formation of artificial electronic kagome bands by reshaping the dispersive Shockley surface state (SS) from the patterning effect of the XHOF. The dispersive Shockley SS exhibits its minimum (SSM) below the Fermi energy (EF), which is at around −100 meV for the Ag(111) surface and −450 meV for the Au(111) surface, respectively.