Spin-dependent edge states in two-dimensional Dirac materials with a flat band
| Autor: | Ye, Li-Li, Han, Chen-Di, Lai, Ying-Cheng |
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| Rok vydání: | 2024 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 108 (2023), 235404 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.108.235404 |
| Popis: | The phenomenon of spin-dependent quantum scattering in two-dimensional (2D) pseudospin-1/2 Dirac materials leading to a relativistic quantum chimera was recently uncovered. We investigate spin-dependent Dirac electron optics in 2D pseudospin-1 Dirac materials, where the energy-band structure consists of a pair of Dirac cones and a flat band. In particular, with a suitable combination of external electric fields and a magnetic exchange field, electrons with a specific spin orientation (e.g., spin-down) can be trapped in a class of long-lived edge modes, generating resonant scattering. The spin-dependent edge states are a unique feature of flat-band Dirac materials and have no classical correspondence. However, electrons with the opposite spin (i.e., spin up) undergo conventional quantum scattering with a classical correspondence, which can be understood in the framework of Dirac electron optics. A consequence is that the spin-down electrons produce a large scattering probability with broad scattering angle distribution in both near- and far-field regions, while the spin-up electrons display the opposite behavior. Such characteristically different behaviors of the electrons with opposite spins lead to spin polarization that can be as high as nearly 100%. Comment: 18 pages, 9 figures, journal |
| Databáze: | arXiv |
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