Dresden 2017 – scientific programme

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O: Fachverband Oberflächenphysik

O 79: Electronic Structure of Surfaces: Spectroscopy, Surface States I

O 79.7: Talk

Wednesday, March 22, 2017, 16:45–17:00, WIL C307

Contribution of magnetic dopants to the electronic structure of the Topological Insulator Sb₂Te₃. — •Sonja Schatz¹, Thiago R. F. Peixoto¹, Hendrik Bentmann¹, Oleg E. Tereshchenko², Konstantin A. Kokh², and Friedrich Reinert¹ — ¹Experimentelle Physik VII, Universität Würzburg, D-97074 Würzburg — ²Saint Petersburg State University, 198504 Saint Petersburg, Russia

Doped Topological Insulators with magnetic impurities have been shown to exhibit novel and exotic quantum phenomena. As has been reported recently, V-doped (BiSb)₂Te₃ features an insulating ground state below T_C ∼ 30 K, and it forms a quantum anomalous Hall state below T ∼ 100 mK [1]. For thin films of this system we already reported, that the existence of a 3d impurity band near the Fermi energy is expected to lead to the occurrence of a ferromagnetic superexchance interaction [2]. In this talk we will present studies of the Topological Insulator Sb₂Te₃ doped with different 3d transition metals and compare our results to first-principles calculations [3]. To investigate the electronic structure of these systems, angle-resolved photoemission and absorption experiments were performed in the soft X-ray regime at temperatures around T 30 K. In particular the valence band was observed resonantly at the 2p absorption edge providing element specificity.

[1] C. Z. Chang et al., Nature Materials 14, 473 (2015).

[2] T. Peixoto et al., Physical Review B 94, 195140 (2016).

[3] J.-M. Zhang et al., Physical Review B 88, 235131 (2013).