2015/01/12 by Zhi‐Xin Guo, Zhi-Xin Guo, Atsushi Oshiyama · 17 citations
Materials Science · Physics and Astronomy · #Condensed matter physics #Density functional theory #Dislocation #Electron #Fermi energy #Graphene research and applications #Materials science #Monolayer #Nanotechnology #Optoelectronics #Physics #Quantum and electron transport phenomena #Scanning tunneling microscope #Silicene #Silicon #Stacking fault #Topological Materials and Phenomena #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1088/1367-2630/17/4/045028
published in New Journal of Physics 17(4), 045028 (IOP Publishing) · 24 pages, 11 figures
arxiv created 2015/01/12 · openalex publication_date 2015/04/29 · arxiv updated 2015/05/05 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report on total-energy electronic structure calculations in the density-functional theory performed for the ultra-thin atomic layers of Si on Ag(111) surfaces. We find several distinct stable silicene structures: , 3 × 3, with the thickness of Si increasing from monolayer to quad-layer. The structural bistability and tristability of the multilayer silicene structures on Ag surfaces are obtained, where the calculated transition barriers infer the occurrence of the flip-flop motion at low temperature. The calculated scanning tunneling microscope (STM) images agree well with the experimental observations. We also find the stable existence of 2 × 1 π -bonded chain and 7 × 7 dimer-adatom-stacking fault Si(111)-surface structures on Ag(111), which clearly shows the crossover of silicene-silicon structures for the multilayer Si on Ag surfaces. We further find the absence of the Dirac states for multilayer silicene on Ag(111) due to the covalent interactions of the silicene-Ag interface and Si-Si interlayer. Instead, we find a new state near the Fermi level composed of π orbitals located on the surface layer of multilayer silicene, which satisfies the hexagonal symmetry and exhibits the linear energy dispersion. By examining the electronic properties of 2 × 1 π -bonded chain structures, we find that the surface-related π states of multilayer Si structures are robust on Ag surfaces.