Superconducting switching due to a triplet component in the Pb/Cu/Ni/Cu/Co2Cr1-xFexAly spin-valve structure

Research output: Contribution to journalLetterContributedpeer-review

Contributors

  • Andrey Andreevich Kamashev - , RAS - Zavoisky Physical-Technical Institute, Kazan Scientific Center (Author)
  • Nadir Nurgayazovich Garif'yanov - , RAS - Zavoisky Physical-Technical Institute, Kazan Scientific Center (Author)
  • Aidar Azatovich Validov - , RAS - Zavoisky Physical-Technical Institute, Kazan Scientific Center (Author)
  • Joachim Schumann - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Vladislav Kataev - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Bernd Büchner - , Chair of Experimental Solid State Physics, Leibniz Institute for Solid State and Materials Research Dresden, TUD Dresden University of Technology (Author)
  • Yakov Victorovich Fominov - , RAS - Landau Institute for Theoretical Physics, Moscow Institute of Physics and Technology, Higher School of Economics (Author)
  • Ilgiz Abdulsamatovich Garifullin - , RAS - Zavoisky Physical-Technical Institute, Kazan Scientific Center (Author)

Abstract

We report the superconducting properties of the Co2Cr1-xFexAly/Cu/Ni/Cu/Pb spin-valve structure the magnetic part of which comprises the Heusler alloy layer HA = Co2Cr1-xFexAly with a high degree of spin polarization (DSP) of the conduction band and a Ni layer of variable thickness. The separation between the superconducting transition curves measured for the parallel (α = 0°) and perpendicular (α = 90°) orientation of the magnetization of the HA and the Ni layers reaches up to 0.5 K (α is the angle between the magnetization of two ferromagnetic layers). For all studied samples the dependence of the superconducting transition temperature Tc on α demonstrates a deep minimum in the vicinity of the perpendicular configuration of the magnetizations. This suggests that the observed minimum and the corresponding full switching effect of the spin valve is caused by the long-range triplet component of the superconducting condensate in the multilayer. Such a large effect can be attributed to a half-metallic nature of the HA layer, which in the orthogonal configuration efficiently draws off the spin-polarized Cooper pairs from the space between the HA and Ni layers. Our results indicate a significant potential of the concept of a superconducting spin-valve multilayer comprising a half-metallic ferromagnet, recently proposed by A. Singh et al., Phys. Rev. X 2015, 5, 021019, in achieving large values of the switching effect.

Details

Original languageEnglish
Pages (from-to)1458-1463
Number of pages6
JournalBeilstein journal of nanotechnology
Volume10
Publication statusPublished - 2019
Peer-reviewedYes

Keywords

Keywords

  • Ferromagnet, Proximity effect, Superconductor