title: Robust surface doping of Bi2Se3 by rubidium intercalation.
abstract: Rubidium adsorption on the surface of the topological insulator Bi(2)Se(3) is found to induce a strong downward band bending, leading to the appearance of a quantum-confined two-dimensional electron gas state (2DEG) in the conduction band. The 2DEG shows a strong Rashba-type spin-orbit splitting, and it has previously been pointed out that this has relevance to nanoscale spintronics devices. The adsorption of Rb atoms, on the other hand, renders the surface very reactive, and exposure to oxygen leads to a rapid degrading of the 2DEG. We show that intercalating the Rb atoms, presumably into the van der Waals gaps in the quintuple layer structure of Bi(2)Se(3), drastically reduces the surface reactivity while not affecting the promising electronic structure. The intercalation process is observed above room temperature and accelerated with increasing initial Rb coverage, an effect that is ascribed to the Coulomb interaction between the charged Rb ions. Coulomb repulsion is also thought to be responsible for a uniform distribution of Rb on the surface.
authors: Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark.
authors: Marco
authors: M
authors: Bianchi
authors: Richard C
authors: RC
authors: Hatch
authors: Zheshen
authors: Z
authors: Li
authors: Philip
authors: P
authors: Hofmann
authors: Fei
authors: F
authors: Song
authors: Jianli
authors: J
authors: Mi
authors: Bo B
authors: BB
authors: Iversen
authors: Zakaria M Abd
authors: ZM
authors: El-Fattah
authors: Peter
authors: P
authors: Löptien
authors: Lihui
authors: L
authors: Zhou
authors: Alexander A
authors: AA
authors: Khajetoorians
authors: Jens
authors: J
authors: Wiebe
authors: Roland
authors: R
authors: Wiesendanger
authors: Justin W
authors: JW
authors: Wells
mesh_terms: D001729:Bismuth / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D007364:Intercalating Agents / Q000737:chemistry; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D012413:Rubidium / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D007364:Intercalating Agents; D018036:Selenium Compounds; D012413:Rubidium; D001729:Bismuth