Magnetic-field-induced topological phase transition in Fe-doped (Bi,Sb)$_2$Se$_3$ heterostructures
| Autor: | Satake, Y., Shiogai, J., Mazur, G. P., Kimura, S., Awaji, S., Fujiwara, K., Nojima, T., Nomura, K., Souma, S., Sato, T., Dietl, T., Tsukazaki, A. |
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| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | Phys. Rev. Materials 4, 044202 (2020) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevMaterials.4.044202 |
| Popis: | Three-dimensional topological insulators (3D-TIs) possess a specific topological order of electronic bands, resulting in gapless surface states via bulk-edge correspondence. Exotic phenomena have been realized in ferromagnetic TIs, such as the quantum anomalous Hall (QAH) effect with a chiral edge conduction and a quantized value of the Hall resistance ${R_{yx}}$. Here, we report on the emergence of distinct topological phases in paramagnetic Fe-doped (Bi,Sb)${_2}$Se${_3}$ heterostructures with varying structure architecture, doping, and magnetic and electric fields. Starting from a 3D-TI, a two-dimensional insulator appears at layer thicknesses below a critical value, which turns into an Anderson insulator for Fe concentrations sufficiently large to produce localization by magnetic disorder. With applying a magnetic field, a topological transition from the Anderson insulator to the QAH state occurs, which is driven by the formation of an exchange gap owing to a giant Zeeman splitting and reduced magnetic disorder. Topological phase diagram of (Bi,Sb)${_2}$Se${_3}$ allows exploration of intricate interplay of topological protection, magnetic disorder, and exchange splitting. Comment: 31 pages, 4 figures and supplementary 30 pages, 11 figures |
| Databáze: | arXiv |
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