The superconducting absolute spin valve

ORAL

Abstract

A ferromagnetic insulator, such as EuS, in contact with a superconductor drives an exchange field resulting in a splitting of the Bardeen-Cooper-Schrieffer density of states by a magnitude proportional to its magnetization [1]. It was suggested that the combination of two such spin-split superconductors could implement an ideal spin valve [2]: a hybrid ferromagnetic-superconducting tunnel junction where the transport of one of the spin species is open while it is completely blocked for the other. Here we report on a switchable superconducting spin-valve based on two EuS/Al bilayers coupled through a tunnel barrier. Our devices exhibit a relative differential resistance variation -between the parallel and antiparallel configuration of the EuS layers- up to almost 1000%. Our devices implement an efficient spin polarized current source and can be exploited as switching logical elements in a memory cell to be used in cryogenics superconductor-based computers.

[1] E. Strambini et al, Phys. Rev. Materials 1, 054402 (2017)
[2] D. Huertas-Hernando, et al., Physical Review Letters 88(4), 47003 (2002)

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Presenters

  • Giorgio De Simoni

    • NEST, Istituto Nanoscienze-CNR & Scuola Normale Superiore
    • NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore
    • NEST Istituto Nanoscienze-CNR and Scuola Normale Superiore

Authors

  • Giorgio De Simoni

    • NEST, Istituto Nanoscienze-CNR & Scuola Normale Superiore
    • NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore
    • NEST Istituto Nanoscienze-CNR and Scuola Normale Superiore

  • Elia Strambini

    • NEST, Istituto Nanoscienze-CNR & Scuola Normale Superiore
    • NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore
    • NEST Istituto Nanoscienze-CNR and Scuola Normale Superiore

  • Jagadeesh Moodera

    • Physics, MIT
    • Physics, Massachusetts Institute of Technology
    • Department of Physics and Francis Bitter Magnet Lab, Massachusetts Institute of Technology
    • Department of Physics and Francis Bitter Magnet Lab, Massachusetts Institute of Technology,
    • Department of Physics, Massachusetts Institute of Technology
    • MIT
    • Department of Physics, Massachussetts Institute of Technology

  • Fernando Bergeret

    • Centro de Fisica de Materiales (CFM-MPC)
    • Centro de Fisica de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, Manuel de Lardizabal 5

  • Francesco Giazotto

    • NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore di Pisa
    • NEST, Istituto Nanoscienze-CNR & Scuola Normale Superiore
    • NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore
    • NEST Istituto Nanoscienze-CNR and Scuola Normale Superiore