Influence of Doping on the Topological Surface States of Crystalline Bi2Se3 Topological Insulators

Kamil Nowak; Michał Jurczyszyn; Maciej Chrobak; Krzysztof Maćkosz; Andrii Naumov; Natalia Olszowska; Marcin Rosmus; Ireneusz Miotkowski; Andrzej Kozłowski; Marcin Sikora; Marek Przybylski

doi:10.3390/ma15062083

Influence of Doping on the Topological Surface States of Crystalline Bi₂Se₃ Topological Insulators

Materials (Basel). 2022 Mar 11;15(6):2083. doi: 10.3390/ma15062083.

Authors

Kamil Nowak^{1

2}, Michał Jurczyszyn², Maciej Chrobak^{1

2}, Krzysztof Maćkosz^{1

2}, Andrii Naumov², Natalia Olszowska³, Marcin Rosmus^{3

4}, Ireneusz Miotkowski⁵, Andrzej Kozłowski¹, Marcin Sikora², Marek Przybylski^{1

2}

Affiliations

¹ Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 30-059 Krakow, Poland.
² Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, 30-059 Krakow, Poland.
³ National Synchrotron Radiation Centre, Jagiellonian University, 30-392 Krakow, Poland.
⁴ Marian Smoluchowski Institute of Physics, Jagiellonian University, 30-348 Krakow, Poland.
⁵ Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907, USA.

Abstract

We present STM/STS, ARPES and magnetotransport studies of the surface topography and electronic structure of pristine Bi₂Se₃ in comparison to Bi_1.96Mg_0.04Se₃ and Bi_1.98Fe_0.02Se₃. The topography images reveal a large number of complex, triangle-shaped defects at the surface. The local electronic structure of both the defected and non-defected regions is examined by STS. The defect-related states shift together with the Dirac point observed in the undefected area, suggesting that the local electronic structure at the defects is influenced by doping in the same way as the electronic structure of the undefected surface. Additional information about the electronic structure of the samples is provided by ARPES, which reveals the dependence of the bulk and surface electronic bands on doping, including such parameters as the Fermi wave vector. The subtle changes of the surface electronic structure by doping are verified with magneto-transport measurements at low temperatures (200 mK) allowing the detection of Shubnikov-de Haas (SdH) quantum oscillations.

Keywords: Bi2Se3; local electronic structure; magnetic dopants; structural defects; topological insulators.

Abstract

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