Proximity Effect in Superconducting Heterostructures with Strong Spin-Orbit Coupling and Spin Splitting
| Autor: | Yao Lu, Tero T. Heikkilä |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
suprajohtavuus
Field (physics) FOS: Physical sciences Field strength 02 engineering and technology 01 natural sciences suprajohteet Superconductivity (cond-mat.supr-con) 0103 physical sciences Mesoscale and Nanoscale Physics (cond-mat.mes-hall) magnetismi 010306 general physics Spin-½ Physics Condensed matter physics Condensed Matter - Mesoscale and Nanoscale Physics Condensed Matter - Superconductivity Spin–orbit interaction Disordered Systems and Neural Networks (cond-mat.dis-nn) Condensed Matter - Disordered Systems and Neural Networks 021001 nanoscience & nanotechnology Ferromagnetism T-symmetry Cooper pair 0210 nano-technology Proximity effect (atomic physics) |
| Popis: | It has been shown that singlet Cooper pairs can be converted into triplet ones and diffuse into a ferromagnet over a long distance in a phenomenon known as the long-range proximity effect (LRPE). This happens in materials with inhomogeneous magnetism or spin-orbit coupling (SOC). Most of the previous studies focus on the cases with small SOC and exchange field. However, the physics was not clear when SOC and exchange field strength are both much greater than the disorder strength. In this work, we consider a two dimensional system with a large Rashba-type SOC and exchange field in the case where only one band is partially occupied. We develop a generalized quasiclassical theory by projecting the Green function onto the partially occupied band (POB). We find that when the SOC energy scale is comparable with the exchange field, there is no LRPE. The reason is that the nonmagnetic impurities together with the large SOC and exchange field can effectively generate spin-flip scattering, which suppresses the proximity effect. We also show that when increasing either SOC or exchange field, the decay length of superconducting correlations can be significantly increased due to an approximately restored time reversal symmetry or spin rotation symmetry around the $z$ (out-of-plane) axis. 10 pages, 5 figures |
| Databáze: | OpenAIRE |
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