Interplay of Umklapp scattering and Sb-Au hybridization in surface-reconstructed Sb/Au(111)
Surface reconstructions induced by atomic adsorption can strongly reshape metallic surface states, providing a direct pathway to tune their electronic structure. Using angle-resolved photoemission spectroscopy, we investigate the electronic structure of Sb/Au(111) during the coverage-driven evolution from the clean Au(111) surface to the $(14\times14)$ and Rec$(3\times\sqrt{3})$ phases. In the Rec$(3\times\sqrt{3})$ phase, triangular Fermi pockets emerge at the Brillouin-zone boundary. Their momentum positions are consistent with a reciprocal-space folding construction, but their reduced size near the Fermi level indicates a modification of the Au-derived $sp$ dispersion. The substantial modifications of deeper Au $d$-derived bands observed in ARPES further indicate significant mixing between Sb $p$ orbitals and Au $d$ states. These results show that the electronic structure of Sb/Au(111) is governed by the interplay between reconstruction-induced Umklapp scattering and interfacial orbital hybridization, highlighting adsorbate-substrate hybridization as a key mechanism for tuning and engineering surface electronic structures.