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Spin and electronic structure of the topological insulator Bi1.5Sb0.5Te1.8Se1.2

Filianina, M. V.; Klimovskikh, I. I.; Shvets, I. A.; Rybkin, A. G.; Petukhov, A. E.; Chulkov, E. V.; Golyashov, V. A.; Kokh, K. A.; Tereshchenko, O. E. and Polley, C. LU , et al. (2018) In Materials Chemistry and Physics 207. p.253-258
Abstract

Electronic and spin structure of the Dirac-cone-like topological surface and valence band states were studied experimentally and theoretically for topological insulator with fractional stoichiometry Bi1.5Sb0.5Te1.8Se1.2 which is considered as one of the best candidates for efficient spin-polarized current generation. By means of spin- and angle-resolved photoelectron spectroscopy we demonstrate the separation of the Dirac point from the bulk states and the helical spin structure of the Dirac cone. For the freshly cleaved surface the Fermi level is located in the bulk band gap and an exposure in residual gases shifts the Fermi level towards the bulk conduction band. Results of the theoretical... (More)

Electronic and spin structure of the Dirac-cone-like topological surface and valence band states were studied experimentally and theoretically for topological insulator with fractional stoichiometry Bi1.5Sb0.5Te1.8Se1.2 which is considered as one of the best candidates for efficient spin-polarized current generation. By means of spin- and angle-resolved photoelectron spectroscopy we demonstrate the separation of the Dirac point from the bulk states and the helical spin structure of the Dirac cone. For the freshly cleaved surface the Fermi level is located in the bulk band gap and an exposure in residual gases shifts the Fermi level towards the bulk conduction band. Results of the theoretical calculations are in a good agreement with the experimental data. Surface morphology study shows a well-structured atomically sharp surface after cleavage. The transport measurements confirm that this topological insulator has relatively high resistance with semiconductor-like temperature dependence at low temperatures. The studied Bi1.5Sb0.5Te1.8Se1.2 crystals demonstrated a quite large Seebeck coefficient values reaching −400 μV/K at room temperature.

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publication status
published
subject
keywords
ARPES, Electronic structure, Topological insulators
in
Materials Chemistry and Physics
volume
207
pages
6 pages
publisher
Elsevier
external identifiers
  • scopus:85041488706
ISSN
0254-0584
DOI
10.1016/j.matchemphys.2017.12.035
language
English
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yes
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4be52024-61a0-4c22-98f3-535f9ddf6809
date added to LUP
2018-02-20 13:08:39
date last changed
2018-05-29 10:33:16
@article{4be52024-61a0-4c22-98f3-535f9ddf6809,
  abstract     = {<p>Electronic and spin structure of the Dirac-cone-like topological surface and valence band states were studied experimentally and theoretically for topological insulator with fractional stoichiometry Bi<sub>1.5</sub>Sb<sub>0.5</sub>Te<sub>1.8</sub>Se<sub>1.2</sub> which is considered as one of the best candidates for efficient spin-polarized current generation. By means of spin- and angle-resolved photoelectron spectroscopy we demonstrate the separation of the Dirac point from the bulk states and the helical spin structure of the Dirac cone. For the freshly cleaved surface the Fermi level is located in the bulk band gap and an exposure in residual gases shifts the Fermi level towards the bulk conduction band. Results of the theoretical calculations are in a good agreement with the experimental data. Surface morphology study shows a well-structured atomically sharp surface after cleavage. The transport measurements confirm that this topological insulator has relatively high resistance with semiconductor-like temperature dependence at low temperatures. The studied Bi<sub>1.5</sub>Sb<sub>0.5</sub>Te<sub>1.8</sub>Se<sub>1.2</sub> crystals demonstrated a quite large Seebeck coefficient values reaching −400 μV/K at room temperature.</p>},
  author       = {Filianina, M. V. and Klimovskikh, I. I. and Shvets, I. A. and Rybkin, A. G. and Petukhov, A. E. and Chulkov, E. V. and Golyashov, V. A. and Kokh, K. A. and Tereshchenko, O. E. and Polley, C. and Balasubramanian, T. and Leandersson, M. and Shikin, A. M.},
  issn         = {0254-0584},
  keyword      = {ARPES,Electronic structure,Topological insulators},
  language     = {eng},
  month        = {03},
  pages        = {253--258},
  publisher    = {Elsevier},
  series       = {Materials Chemistry and Physics},
  title        = {Spin and electronic structure of the topological insulator Bi<sub>1.5</sub>Sb<sub>0.5</sub>Te<sub>1.8</sub>Se<sub>1.2</sub>},
  url          = {http://dx.doi.org/10.1016/j.matchemphys.2017.12.035},
  volume       = {207},
  year         = {2018},
}