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

Evidence for spin-dependent energy transport in a superconductor

In systems where the spin states have different energy distributions, the different spin populations can carry different heat currents, in what is known as the spin-energy mode. Here, using spin-resolved spectroscopy, the authors demonstrate the existence of a spin-energy mode in a superconductor