Experimental Demonstration of a Magnetically Induced Warping Transition in a Topological Insulator Mediated by Rare-Earth Surface Dopants

Magnetic topological insulators constitute a novel class of materials whose topological surface states (TSSs) coexist with long-range ferromagnetic order, eventually breaking time-reversal symmetry. The subsequent bandgap opening is predicted to co-occur with a distortion of the TSS warped shape fro...

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Detalles Bibliográficos
Autores: Muñiz Cano, Beatriz|||0000-0002-9338-7077, Ferreiros, Yago, Pantaleón, Pierre A., Dai, Ji|||0000-0003-1388-6843, Tallarida, Massimo, Figueroa García, Adriana Isabel|||0000-0002-8498-9383, Marinova, Vera|||0000-0002-3499-0212, García-Díez, Kevin|||0000-0001-8093-904X, Mugarza, Aitor|||0000-0002-2698-885X, Valenzuela, Sergio O.|||0000-0002-4632-8891, Miranda, Rodolfo, Camarero, Julio|||0000-0003-0078-7280, Guinea, Francisco|||0000-0001-5915-5427, Silva-Guillén, Jose Angel|||0000-0002-0483-5334, Valbuena, Miguel Ángel|||0000-0002-0585-5636
Tipo de recurso: artículo
Fecha de publicación:2023
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:283423
Acceso en línea:https://ddd.uab.cat/record/283423
https://dx.doi.org/urn:doi:10.1021/acs.nanolett.3c00587
Access Level:acceso abierto
Palabra clave:Magnetic topological insulators
Rare-earth doping
Topological surface state
Time-reversal symmetry breaking
Angle-resolved photoemission spectroscopy
Quantum anomalous Hall effect
Descripción
Sumario:Magnetic topological insulators constitute a novel class of materials whose topological surface states (TSSs) coexist with long-range ferromagnetic order, eventually breaking time-reversal symmetry. The subsequent bandgap opening is predicted to co-occur with a distortion of the TSS warped shape from hexagonal to trigonal. We demonstrate such a transition by means of angle-resolved photoemission spectroscopy on the magnetically rare-earth (Er and Dy) surface-doped topological insulator BiSeTe. Signatures of the gap opening are also observed. Moreover, increasing the dopant coverage results in a tunable p-type doping of the TSS, thereby allowing for a gradual tuning of the Fermi level toward the magnetically induced bandgap. A theoretical model where a magnetic Zeeman out-of-plane term is introduced in the Hamiltonian governing the TSS rationalizes these experimental results. Our findings offer new strategies to control magnetic interactions with TSSs and open up viable routes for the realization of the quantum anomalous Hall effect.

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