| Autor: |
Cano, Beatriz Muñiz, Ferreiros, Yago, Pantaleón, Pierre A., Dai, Ji, Tallarida, Massimo, Figueroa, Adriana I., Marinova, Vera, Díez, Kevin García, Mugarza, Aitor, Valenzuela, Sergio O., Miranda, Rodolfo, Camarero, Julio, Guinea, Francisco, Silva-Guillén, Jose Angel, Valbuena, Miguel A. |
| Rok vydání: |
2023 |
| Předmět: |
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| Druh dokumentu: |
Working Paper |
| DOI: |
10.1021/acs.nanolett.3c00587 |
| Popis: |
Magnetic topological insulators (MTI) constitute a novel class of materials where the topologically protected band structure coexists with long-range ferromagnetic order, which can lead to the breaking of time-reversal symmetry (TRS), introducing a bandgap in the Dirac cone-shaped topological surface state (TSS). The gap opening in MITs has been predicted to be accompanied by a distortion in the TSS, evolving its warped shape from hexagonal to trigonal. In this work, we demonstrate such a transition by means of angle-resolved photoemission spectroscopy after the deposition of low concentrations of magnetic rare earths, namely Er and Dy, on the ternary three-dimensional prototypical topological insulator Bi$_2$Se$_2$Te. Signatures of the gap opening occurring as a consequence of the TRS breaking have also been observed, whose existence is supported by the observation of the aforementioned transition. Moreover, increasing the Er coverage results in a tunable p-type doping of the TSS. As a consequence, the Fermi level (E$_{\textrm{F}}$) of our Bi$_2$Se$_2$Te crystals can be gradually tuned towards the TSS Dirac point, and therefore to the magnetically induced bandgap; thus fulfilling two of the necessary prerequisites for the realization of the quantum anomalous Hall effect (QAHE) in this system. The experimental results are rationalized by a theoretical model where a magnetic Zeeman out-of-plane term is introduced in the hamiltonian governing the TSS band dispersion. Our results offer new strategies to control magnetic interactions with TSSs based on a simple approach and open up viable routes for the realization of the QAHE. |
| Databáze: |
arXiv |
| Externí odkaz: |
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