Macroscopic quantum dynamics of pi-junction with ferromagnetic insulators

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

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36 Citations (Scopus)

Abstract

We theoretically investigate the macroscopic quantum dynamics of a π junction with a superconductor (S) and a multiferroic material or a ferromagnetic insulator (FI). By deriving the effective action from a microscopic Hamiltonian, a π-junction qubit (a S-FI-S superconducting quantum interference device ring) 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. We also investigate macroscopic quantum tunneling (MQT) in current-biased S-FI-S π junctions and show that the influence of the quasiparticle dissipation on MQT is negligibly small.
Original languageUndefined
Pages (from-to)180502-
JournalPhysical review B: Condensed matter and materials physics
Volume74
Issue number18
DOIs
Publication statusPublished - 2006

Keywords

  • IR-74266
  • METIS-233434

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