Macroscopic quantum dynamics of pi-junctions with ferromagnetic insulators
Mesoscale and Nanoscale Physics
2007-05-23 v2 Superconductivity
Quantum Physics
Abstract
We theoretically investigate the macroscopic quantum dynamics of a pi junction with a superconductor (S) and a multiferroic material or a ferromagnetic insulator (FI). By deriving the effective action from a microscopic Hamiltonian, a pi-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 pi junctions and show that the influence of the quasiparticle dissipation on MQT is negligibly small.
Keywords
Cite
@article{arxiv.cond-mat/0608709,
title = {Macroscopic quantum dynamics of pi-junctions with ferromagnetic insulators},
author = {Shiro Kawabata and Satoshi Kashiwaya and Yasuhiro Asano and Yukio Tanaka and Alexander A. Golubov},
journal= {arXiv preprint arXiv:cond-mat/0608709},
year = {2007}
}
Comments
4 pages, 2 figures