Spontaneous currents and half-integer Shapiro steps in Superconductor-Ferromagnet-Superconductor 0-pi Josephson junctions
Superconductivity
2007-05-23 v1 Mesoscale and Nanoscale Physics
Abstract
We study Superconductor-Ferromagnet-Superconductor (Nb-Cu0.47 Ni0.53-Nb) Josephson junctions with spatial variations in the barrier thickness. Critical current vs. magnetic flux diffraction patterns indicate that the critical current density changes sign along the width of the junctions, creating interfaces between 0 and pi junction regions around which spontaneous currents can circulate. Shapiro steps observed at half-integer Josephson voltages can be explained by the phase-locking of the spontaneous circulating currents to the applied rf modulation.
Cite
@article{arxiv.cond-mat/0506003,
title = {Spontaneous currents and half-integer Shapiro steps in Superconductor-Ferromagnet-Superconductor 0-pi Josephson junctions},
author = {S. M. Frolov and D. J. Van Harlingen and V. V. Bolginov and V. A. Oboznov and V. V. Ryazanov},
journal= {arXiv preprint arXiv:cond-mat/0506003},
year = {2007}
}
Comments
4 pages, 4 figures