Berlin 2012 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 21: [MA] Joint Session "Topological Insulators I" (jointly with DS, HL, O, TT)
O 21.3: Vortrag
Montag, 26. März 2012, 18:15–18:30, H 1012
Ab initio study of Rashba splitting of 2DEG at the surfaces of topological insulators — Sergey V. Eremeev1,2, •Maia G. Vergniory3,4, Tatiana V. Menshchikova2, and Evgueni V. Chulkov4,5,6 — 1Institue of Strength and Materials Science, Tomsk, Russia — 2Tomsk State University, Tomsk, Russia — 3Max Planck Institute of Microstructure Physics, Halle, Germany — 4Donostia International Physics Center, Donostia, Spain — 5Departamento de Fisica de Materiales UPV/EHU, Donostia, Spain — 6Centro de Fisica de Materiales CFM-MPC and Centro Mixto CSIC-UPV/EHU, Donostia, Spain
The surface of three dimensional topological insulators (TI) holds a metallic surface state (SS) with Dirac dispersion. Recently it has been demonstrated by using Angle Resolved Photoemission Spectroscopy (ARPES) that besides de Dirac cone 2D electron gas (2DEG) arise at the surface of Bi2Se3 and Bi2Te3 after a few hours of exposition in vacuum or upon deposition of atoms. In this work by means of DFT ab initio calculations we present a new interpretation for the driving mechanism of the simultaneous formation and evolution of the parabolic and M-shaped 2D electron gas (2DEG) bands at the surface of Topological Insulators. As it has been probed in previous publications [7,8] it might be due to an expansion of the van der Waals spacing produced by impurities intercalation. We will show the effect of these expansions on the spatial relocalization of the Dirac cone and we will compare our results with some experimental data for different binary and ternary compounds.