Long-range spin-polarized quasiparticle transport in mesoscopic Al superconductors with a Zeeman splitting

Abstract

We report on nonlocal transport in multiterminal superconductor-ferromagnet structures, which were fabricated by means of e-beam lithography and shadow evaporation techniques. In the presence of a significant Zeeman splitting of the quasiparticle states, we find signatures of spin transport over distances of several μm, exceeding other length scales such as the coherence length, the normal-state spin-diffusion length, and the charge-imbalance length. The relaxation length of the spin signal shows a nearly linear increase with magnetic field, hinting at a freeze-out of relaxation by the Zeeman splitting. We propose that the relaxation length is given by the recombination length of the quasiparticles rather than a renormalized spin-diffusion length.

5 pages, 4 figures, revtex

References in corpus (6)

• Extremely long quasiparticle spin lifetimes in superconducting aluminium using MgO tunnel spin injectors
• Spin injection and relaxation in a mesoscopic superconductor
• Superconductors as ideal spin sources for spintronics
• Charge imbalance in superconductors in the low-temperature limit
• Spin Transport in Diffusive Superconductors
• Nonlocal conductance via overlapping Andreev bound states in ferromagnet-superconductor heterostructures

Cited by in corpus (3)

• Spin Imbalance and Spin-Charge Separation in a Mesoscopic Superconductor
• Spin injection from a normal metal into a mesoscopic superconductor
• Effect of a magnetic field on the quasiparticle recombination in superconductors