Spin imbalance in hybrid superconducting structures with spin-active interfaces

Abstract

We consider a heterostructure consisting of a normal metal and a superconductor separated by a spin-active interface. At finite-bias voltages, spin-filtering and spin-mixing effects at the interface allow for an induced magnetization (spin imbalance) on the superconducting side of the junction, which relaxes to zero in the bulk. Such interfaces are also known to host a pair of in-gap Andreev bound states which were recently observed experimentally. We show that these states are responsible for the dominant contribution to the induced spin imbalance close to the interface. Motivated by recent experiments on spin-charge density separation in superconducting aluminum wires, we propose an alternative way to observe spin imbalance without applying an external magnetic field. We also suggest that the peculiar dependence of the spin imbalance on the applied bias voltage permits an indirect bound-state spectroscopy.

7 pages, 4 figures

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Cited by in corpus (4)

• General framework for transport in spin-orbit-coupled superconducting heterostructures: Nonuniform spin-orbit coupling and spin-orbit-active interfaces
• Quasiclassical theory of charge transport across mesoscopic normal metal-superconducting heterostructures with current conservation
• Spin-polarized currents and noise in NS junctions with Yu-Shiba-Rusinov impurities
• Quantum kinetic equations and anomalous non-equilibrium Cooper pair spin accumulation in Rashba wires with Zeeman splitting