Current-induced spin polarisation in Rashba–Dresselhaus systems under different point groups
Non-magnetic materials without inversion symmetry typically exhibit strong Rashba spin–orbit coupling (SOC), enabling the well-known Rashba Edelstein effect where an external electrical current induces transverse spin polarisation. In this study, we demonstrate that electrically induced spin polaris...
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| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/adac88 |
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| Summary: | Non-magnetic materials without inversion symmetry typically exhibit strong Rashba spin–orbit coupling (SOC), enabling the well-known Rashba Edelstein effect where an external electrical current induces transverse spin polarisation. In this study, we demonstrate that electrically induced spin polarisation in non-magnetic materials, for example, electronic systems within quantum-well geometries, can significantly be influenced by the system’s point-group symmetries, such as C _n and C _nv . These symmetries allow various linear and higher-order momentum, $k-$ varying SOC Hamiltonian. Specifically, we show that surfaces having C _n point-group symmetry, which permits specific linear and cubic Rashba and Dresselhaus SOC terms, can lead to both orthogonal and non-orthogonal spin polarisations with respect to the applied field. In contrast, surfaces with C _nv symmetry exhibit only transverse spin polarisation, regardless of the linear and cubic SOC terms. We further find contrasting spin polarisation for cubic-in- k SOC as compared to the linear-in- k SOC when energy is varied, for example, through doping. Additionally, we show that the surfaces with C _n symmetry may exhibit persistent spin current, depending on the relative strength between different momentum-dependent SOC terms. Our finding emphasizes the significance of crystal symmetry in understanding and manipulating induced spin polarisation in noncentrosymmetric materials, especially in surface/interface systems. |
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| ISSN: | 1367-2630 |