Van Hove Singularity and Rashba Spin-splitting on Antimonene/Bi(111) Moiré Superlattice

We demonstrate that single- and double-bilayer antimony honeycomb lattices (antimonene) form moiré superlattices on a Bi(111) substrate due to lattice mismatch. Scanning tunneling microscopy (STM) and angle-resolved photoemission spectroscopy (ARPES), combined with density functional theory (DFT) calculations, reveal that the surface band structure features saddle points near the Fermi level, leading to van Hove singularities. Furthermore, spin-resolved ARPES measurements show that the observed surface states are Rashba-type spin-polarized, similar to those in Bi(111). These properties offer fascinating implications for the possible coexistence of strong electron correlations and topologically protected electronic states.