Regensburg 2016 – scientific programme

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O: Fachverband Oberflächenphysik

O 47: Electronic Structure of Surfaces: Spectroscopy, Surface States

O 47.13: Poster

Tuesday, March 8, 2016, 18:15–20:30, Poster E

Probing the electronic structure of epitaxially grown topological insulators with varying magnetic doping — •Sonja Schatz¹, Mohammed Al-Baidhani¹, Thiago R. F. Peixoto¹, Henriette Maaß¹, Christoph Seibel¹, Hendrik Bentmann¹, Grzegorz Karczewski^2,3, Steffen Schreyeck², Martin Winnerlein², Charles Gould², Karl Brunner², Laurens Molenkamp², and Friedrich Reinert¹ — ¹Experimentelle Physik VII, Universität Würzburg, D-97074 Würzburg — ²Experimentelle Physik III, Universität Würzburg, D-97074 Würzburg — ³Institute of Physics, Polish Academy of Science, 02-668 Warsaw, Poland

We will present an overview of recent photoelectron spectroscopy (PES) studies of epitaxial topological insulator (TI) thin films. In particular, we investigated (BiSb)₂Te₃ layers with a particular focus on magnetic doping with V and Cr impurities. X-ray photoemission (XPS) and absorption measurements of the 2p core level lines provide information on the incorporation of the impurities in the TI host material. Resonant PES allows us to address the V 3d states in the valence band which are expected to play a crucial role for the exotic magnetic and transport properties of these systems. Furthermore, angle-resolved PES of the topological surface state in Bi₂Se₂Te films will be presented, focusing on anisotropy effects in the Fermi surface [1]. The strength of the anisotropy lies between Bi₂Se₃ and Bi₂Te₃. Angle-dependent XPS is used to characterize chemical shifts in the core level lines and to obtain information of the chemical composition near the surface [1].

[1] H. Maaß et al., J. Appl. Phys. 116, 193708, (2014)