Presentation Information
[1P23]Study of structural phase diagram and electronic states of Sb-induced surface superstructures on Ge(111)
*Honoka Otsuka1, Lars Konermann1, Masaki Imamura2, Kazutoshi Takahashi2, Akari Takayama1,3 (1. Graduate School of Advanced Science and Engineering, Waseda University, 2. Saga University Synchrotron Light Application Center, 3. Institute of Multidisciplinary Research for Advanced Materials, Tohoku University)
In surface superstructures, unique physical properties are exhibited due to the breaking of spatial inversion symmetry. The Rashba effect has been reported in surface superstructures with heavy elements, thus various studies are being conducted to elucidate the details of the spin-splitting electronic state caused by the Rashba effect. In antimony (Sb), a group-V semimetal, spin-splitting bands caused by the Rashba effect have been reported on its crystal surface, suggesting that the Rashba effect may occur in Sb-induced surface superstructures. However, few such structures have been reported, and their electronic states remain poorly understood. In this research, we investigate the structural phase diagram of Sb-induced surface superstructures on Ge(111) and their electronic states using ARPES. We discovered a previously unreported 7×7 structure by depositing 0.4 ML of Sb and annealing at 730 K. This presentation will introduce the structural phase diagram of the Sb/Ge(111) surface superstructure, detailing sample preparation conditions, and will also showcase the electronic states of the 7×7 structure as determined by ARPES.