Ab initio k.p theory of spin-momentum locking: Application to topological surface states
| Autor: | Nechaev, I. A., Krasovskii, E. E. |
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| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 102, 115437 (2020) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.102.115437 |
| Popis: | Based on ab initio relativistic ${\mathbf k}\cdot{\mathbf p}$ theory, we derive an effective two-band model for surface states of three-dimensional topological insulators up to seventh order in $\mathbf{k}$. It provides a comprehensive description of the surface spin structure characterized by a non-orthogonality between momentum and spin. We show that the oscillation of the non-orthogonality with the polar angle of $\mathbf{k}$ with a $\pi/3$ periodicity can be seen as due to effective six-fold symmetric spin-orbit magnetic fields with a quintuple and septuple winding of the field vectors per single rotation of $\mathbf{k}$. Owing to the dominant effect of the classical Rashba field, there remains a single-winding helical spin structure but with a periodic few-degree deviation from the orthogonal locking between momentum and spin. Comment: 8 pages, 3 figures, 2 tables |
| Databáze: | arXiv |
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