Cooper pair transport and miacroscopic quantum dynamics in Josephson juncitons through ferromagnetic insulators

S. Kawabata, Shiro Kawabata, Yasuhiro Asano, Yukio Tanaka, Satoshi Kashiwaya, Alexandre Avraamovitch Golubov

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10 Citations (Scopus)


We theoretically investigate the cooper pair transport and the macroscopic quantum dynamics of a Josephson junction with a superconductor (S) and a ferromagnetic insulator (FI). By use of the recursive Green’s function method, we numerically found the formation of the π junction in the case of the fully spin-polarized FI. On the other hand, the Josephson current through the spin filtering barrier does not show the π junction behaviors. By deriving the effective action from microscopic Hamiltonian, a π junction flux qubit is proposed. In this qubit, a quantum two-level system is spontaneously generated and the effect of the quasiparticle dissipation is found to be very weak. These features make it possible to realize a quiet qubit with high coherency.
Original languageUndefined
Pages (from-to)701-
JournalPhysica C
Issue number7-10
Publication statusPublished - 2008


  • IR-79058
  • Green’s function method
  • Ferromagnetic insulator
  • METIS-252559
  • Josephson junction
  • Spintronics
  • Quantum computer

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