Quasiparticle spin resonance and coherence in superconducting aluminium.
Conventional superconductors were long thought to be spin inert; however, there is now increasing interest in both (the manipulation of) the internal spin structure of the ground-state condensate, as well as recently observed long-lived, spin-polarized excitations (quasiparticles). We demonstrate spin resonance in the quasiparticle population of a mesoscopic superconductor (aluminium) using novel on-chip microwave detection techniques. The spin decoherence time obtained (∼100 ps), and its dependence on the sample thickness are consistent with Elliott-Yafet spin-orbit scattering as the main decoherence mechanism. The striking divergence between the spin coherence time and the previously measured spin imbalance relaxation time (∼10 ns) suggests that the latter is limited instead by inelastic processes. This work stakes out new ground for the nascent field of spin-based electronics with superconductors or superconducting spintronics.
Laboratoire de Physique des Solides (CNRS UMR 8502), Bâtiment 510, Université Paris-Sud 91405 Orsay, France.
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Quay
Laboratoire de Physique des Solides (CNRS UMR 8502), Bâtiment 510, Université Paris-Sud 91405 Orsay, France.
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Weideneder
Laboratoire de Physique des Solides (CNRS UMR 8502), Bâtiment 510, Université Paris-Sud 91405 Orsay, France.
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Chiffaudel
Laboratoire de Physique des Solides (CNRS UMR 8502), Bâtiment 510, Université Paris-Sud 91405 Orsay, France.|Institute for Experimental and Applied Physics, University of Regensburg 93040 Regensburg, Germany.
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Strunk
Laboratoire de Physique des Solides (CNRS UMR 8502), Bâtiment 510, Université Paris-Sud 91405 Orsay, France.
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Aprili