Giant spin transport anisotropy in magnetic topological insulators

We report on exceptionally long spin transport and giant spin lifetime anisotropy in the gapped surface states of three-dimensional (3D) magnetic topological insulators (MTIs). We examine the properties of these states using the three-dimensional Fu-Kane-Mele Hamiltonian model in the presence of a m...

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Detalles Bibliográficos
Autores: Vila Tusell, Marc|||0000-0001-9118-421X, Cummings, Aron|||0000-0003-2307-497X, Roche, Stephan|||0000-0003-0323-4665
Tipo de recurso: artículo
Fecha de publicación:2024
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:308334
Acceso en línea:https://ddd.uab.cat/record/308334
https://dx.doi.org/urn:doi:10.1103/PhysRevB.109.195435
Access Level:acceso abierto
Palabra clave:Exchange fields
Hamiltonian models
Magnetic exchange
Out-of-plane
Property
Spin lifetimes
Spin textures
Spin transport
Topological insulators
Two-band model
Descripción
Sumario:We report on exceptionally long spin transport and giant spin lifetime anisotropy in the gapped surface states of three-dimensional (3D) magnetic topological insulators (MTIs). We examine the properties of these states using the three-dimensional Fu-Kane-Mele Hamiltonian model in the presence of a magnetic exchange field. The corresponding spin textures of surface states, which are well reproduced by an effective two-band model, hint at a considerable enhancement of the lifetime of out-of-plane spins compared to in-plane spins. This is confirmed by large-scale spin transport simulations for 3D MTIs with disorder. The energy dependence of the spin lifetime anisotropy arises directly from the nontrivial spin texture of the surface states, and is correlated with the onset of the quantum anomalous Hall phase. Our findings suggest different spin filtering capabilities of the gapped surface MTI states, which could be explored by nonlocal spin valve measurements.