Magnetic properties of Mn-doped Bi2Se3 topological insulators: ab initio calculations

0534792 - FZÚ 2021 RIV US eng J - Journal Article
Carva, K. - Baláž, P. - Šebesta, J. - Turek, I. - Kudrnovský, Josef - Máca, František - Drchal, Václav - Chico, J. - Sechovský, V. - Honolka, Jan
Magnetic properties of Mn-doped Bi2Se3 topological insulators: ab initio calculations.
Physical Review B. Roč. 101, č. 5 (2020), s. 1-12, č. článku 054428. ISSN 2469-9950. E-ISSN 2469-9969
R&D Projects: GA MŠMT(CZ) EF16_019/0000760
Grant - others:OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Institutional support: RVO:68378271
Keywords : topological insulator * Bi₂Se₃ * doping * manganese * Curie temperature * ab initio
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 4.036, year: 2020
Method of publishing: Limited access
https://doi.org/10.1103/PhysRevB.101.054428

Doping Bi2Se3 by Mn dopants is an interesting problem since it may break the time-reversal symmetry needed to maintain the topological insulator character. Different Curie temperatures or no ferromagnetic order are reported for comparable Mn concentrations. We have calculated ab initio the Bi2Se3 electronic structure influenced by Mn dopants, and exchange interactions between them. We have considered two possible Mn positions, the substitutional and interstitial one, and also native defects. We have found a relaxation of atoms around Mn, which affects significantly magnetic interactions. Based on the calculated data we performed spin dynamics simulations to examine systematically the resulting magnetic order for various defect contents. We have found under which conditions the experimentally measured Curie temperatures TC can be reproduced. We predict the change of TC with a shift of Fermi level, which opens the way to tune the system magnetic properties by selective doping.
Permanent Link: http://hdl.handle.net/11104/0312960