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Interference phenomena and long-range proximity effect in clean superconductor-ferromagnet systems.
A S Mel'nikov1, A V Samokhvalov, S M Kuznetsova
1Institute for Physics of Microstructures, Russian Academy of Sciences, 603950 Nizhny Novgorod, GSP-105, Russia.
Physical Review Letters
|February 2, 2013
Summary
We investigated the proximity effect in superconductor-ferromagnet structures. Modulations in the exchange field create long-range supercurrents, explaining phenomena in ferromagnetic nanowires.
Area of Science:
- Condensed matter physics
- Quantum mechanics
Background:
- The proximity effect describes how superconductivity can be induced in a non-superconducting material when placed near a superconductor.
- Understanding this effect in superconductor-ferromagnet structures is crucial for developing advanced electronic devices.
Purpose of the Study:
- To investigate the influence of exchange field variations on the proximity effect in superconductor-ferromagnet systems.
- To elucidate the mechanisms behind long-range supercurrents in these structures.
Main Methods:
- Theoretical analysis of quasiparticle trajectories within superconductor-ferromagnet structures.
- Modeling the impact of spatial and momentum-dependent exchange fields on superconducting correlations.
Main Results:
- Spatial modulation of the exchange field leads to long-range supercurrents via particle-hole interference.
- Momentum dependence of the exchange field, driven by spin-orbit interaction, establishes long-range superconducting correlations even without ferromagnetic domains.
Conclusions:
- Exchange field peculiarities are key drivers of the proximity effect in superconductor-ferromagnet systems.
- The findings provide a theoretical framework for recent experimental observations in ferromagnetic nanowires.
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