@article{oai:nagoya.repo.nii.ac.jp:00007144,
 author = {Kawabata, Shiro and kashiwaya, Satoshi and Asano, Yasuhiro and Tanaka, Yukio and Alexander, A.  Golubov},
 issue = {18},
 journal = {PHYSICAL REVIEW B},
 month = {Nov},
 note = {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.},
 pages = {180502--180502},
 title = {Macroscopic quantum dynamics of π junctions with ferromagnetic insulators},
 volume = {74},
 year = {2006}
}