Interaction of Spin-Polarised Supercurrents with Spin-Orbit Coupling

Jason Robinson, University of Cambridge

July 9, 2021

Spin currents are fundamental to spintronics, but in the normal state large charge currents are required at device inputs in order to generate sufficiently large output spin current densities to perform useful work on a neighbouring ferromagnetic layer. In this talk I will review our group’s progress in generating and controlling superconducting spin currents in superconducting proximity structures with ferromagnetic and heavy metal layers with strong spin-orbit coupling (SOC) [1-2]. In particular, I will show that in agreement with recent theory [3-5] and experiments [2,6], interfacial Rashba-type SOC in conjunction with a magnetic exchange field can generate a spin-polarized spin-triplet channel within a thin-film superconductor. I will also discuss the interaction and decay of spin-triplet supercurrents within non-superconducting Nb with isotropic SOC [7]. The results are central to the development of nonequilibrium superconducting spintronics with charge and spin-degrees of freedom.

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2. K.-R. Jeon et al. Nat. Mater. 17, 499–503 (2018).
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5. X. Montiel, M. Eschrig, Phys. Rev. B 98, 104513 (2018).
6. N. Banerjee et al., Phys. Rev. B 97, 184521 (2018).
7. S. Komori et al., Science Advances 7, eabe0128 (2021).