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...
| Authors: | , , |
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| Format: | article |
| Publication Date: | 2024 |
| Country: | España |
| Institution: | Universitat Autònoma de Barcelona |
| Repository: | Dipòsit Digital de Documents de la UAB |
| Language: | English |
| OAI Identifier: | oai:ddd.uab.cat:308334 |
| Online Access: | https://ddd.uab.cat/record/308334 https://dx.doi.org/urn:doi:10.1103/PhysRevB.109.195435 |
| Access Level: | Open access |
| Keyword: | Exchange fields Hamiltonian models Magnetic exchange Out-of-plane Property Spin lifetimes Spin textures Spin transport Topological insulators Two-band model |
| Summary: | 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. |
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