Observation of Semiconductor‐Based Geometrically Frustrated Lattice in Bilayer FeSb/SrTiO ₃ (001) Films

ABSTRACT 2D geometrically frustrated lattices, such as Kagome and Lieb lattices, host exotic electronic bands including Dirac cones and flat bands, fertilizing the discovery of strong correlated quantum phenomena. However, experimental realization of inorganic Lieb lattices has thus far been limited to artificial structures on metal substrates. Here, we report the observation of electronic Kagome and distorted Lieb lattices on narrow‐bandgap semiconductor bilayer FeSb films epitaxially grown on SrTiO 3 (001) substrates. Combined with density functional theory (DFT) calculations, we reveal that these Kagome and distorted Lieb lattices originate from the Sb‐atom‐reconstructed surface states of Fe‐terminated bilayer FeSb films. Using low‐temperature scanning tunneling microscopy/spectroscopy (STM/STS), we further present experimental signatures that may be associated with flat bands in the distorted Lieb lattice, as well as emergent topological edge states. Our work provides a versatile route to fabricate artificial frustrated lattices with exotic electronic and topological properties, alongside potential seamless integration with state‐of‐the‐art semiconductor technologies.