  In this work, we demonstrate the formation and electronic influence of
lateral heterointerfaces in FeSn containing Kagome and honeycomb layers.
Lateral heterostructures offer spatially resolved property control, enabling
the integration of dissimilar materials and promoting phenomena not typically
observed in vertical heterostructures. Using the molecular beam epitaxy
technique, we achieve a controllable synthesis of lateral heterostructures in
the Kagome metal FeSn. With scanning tunneling microscopy/spectroscopy in
conjunction with first-principles calculations, we provide a comprehensive
understanding of the bonding motif connecting the Fe3Sn-terminated Kagome and
Sn2-terminated honeycomb surfaces. More importantly, we reveal a
distance-dependent evolution of the electronic states in the vicinity of the
heterointerfaces. This evolution is significantly influenced by the orbital
character of the flat bands. Our findings suggest an approach to modulate the
electronic properties of the Kagome lattice, which should be beneficial for the
development of future quantum devices.
