2005/09/06 by A. Yu. Rusanov, Steven Habraken, S. Habraken +1 · 128 citations
Materials Science · Physics and Astronomy · #Andreev reflection #Antiparallel (mathematics) #Condensed matter physics #Ferromagnetism #Iron-based superconductors research #Magnetic field #Magnetic properties of thin films #Magnetization #Materials science #Permalloy #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Quasiparticle #Spin (aerodynamics) #Superconductivity #Yield (engineering) #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.73.060505
published in Physical Review B 73(6) (American Physical Society) · 4 pages, 3 figures
arxiv created 2005/09/06 · openalex publication_date 2006/02/22 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In ferromagnet-superconductor-ferromagnet (F∕S∕F) trilayers where the magnetization directions of the F layers can be controlled separately, it has theoretically been predicted that the antiparallel (AP) configuration can have a higher superconducting transition temperature Tc than the parallel (P) configuration. This is the so-called spin switch, which has been found experimentally for the case of weak ferromagnets. Here we show that strong ferromagnets yield the opposite effect. We study the transport properties of F∕S∕F trilayers with F=Ni0.80Fe0.20 (Permalloy, Py) and S=Nb, structured in strips of different sizes. Using two different thicknesses for the Py layers, we can switch, in a well-defined way, between the AP and P configurations. In the superconducting transition we find a clear increase of the resistance in the AP state. We ascribe this to enhanced reflection of spin-polarized quasiparticles at the S∕F interfaces, which leads to a stronger suppression of superconductivity on the S side.