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Quasiparticle spin resonance and coherence in superconducting aluminium
C H L Quay1, M Weideneder1, Y Chiffaudel1
1Laboratoire de Physique des Solides (CNRS UMR 8502), Bâtiment 510, Université Paris-Sud 91405 Orsay, France.
Nature Communications
|October 27, 2015
Summary
Researchers observed spin resonance in superconductors, revealing insights into spin decoherence and paving the way for superconducting spintronics.
Area of Science:
- Condensed Matter Physics
- Quantum Materials
- Spintronics
Background:
- Superconductors were traditionally considered spin inert.
- Growing interest in manipulating the spin structure of superconducting condensates and spin-polarized quasiparticles.
- Need for understanding spin dynamics in superconductors for advanced electronics.
Purpose of the Study:
- To demonstrate spin resonance in the quasiparticle population of a mesoscopic superconductor.
- To investigate spin decoherence mechanisms in superconductors.
- To explore the potential of superconductors in spintronic applications.
Main Methods:
- Utilized novel on-chip microwave detection techniques.
- Studied a mesoscopic aluminium superconductor.
- Measured spin decoherence time and its dependence on sample thickness.
Main Results:
- Successfully demonstrated spin resonance in the quasiparticle population.
- Obtained a spin decoherence time of approximately 100 picoseconds.
- Spin decoherence time dependence on thickness suggests Elliott-Yafet spin-orbit scattering as the primary mechanism.
- Observed a significant divergence between spin coherence and spin imbalance relaxation times (approx. 10 nanoseconds), indicating inelastic processes limit the latter.
Conclusions:
- Elliott-Yafet spin-orbit scattering is a key mechanism for spin decoherence in mesoscopic superconductors.
- Inelastic processes, not spin relaxation, likely limit spin imbalance relaxation.
- This research opens new avenues for superconducting spintronics and spin-based electronics.
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