First-Principles Prediction of Giant 1D Rashba Splitting in Bismuth-adsorbed Atomic Nanowires

We investigated that bismuth-adsorbed In/Si(111)–4×1 quasi one-dimensional surfaces, using first-principles calculations based on density functional theory. As a result, giant 1D Rashba splittings are observed due to the combination of In/Si(111) one–dimensionality and the spin–orbit coupling. Especially, a metastable surface of 1/4–monolayer bismuth coverage indicates the large out–of–plane spin polarization in Rahsba-split states. We have estimated the magnitude of the spin splitting by the linear approximation of the split width, and obtained the Rashba parameter, 1.8 eVÅ. This is one of the largest values in 1D the Rashba systems.