Josephson vortex

In superconductivity, a Josephson vortex is a vortex of supercurrent in a long Josephson junction (LJJ). The supercurrents circulate around the vortex center which is situated inside the Josephson barrier. Opposite to Abrikosov vortices in type-II superconductors, Josephson vortex has "no normal core".

Usually the Josephson vortex's supercurrents create magnetic field with the total flux equal to $Phi\_0$ --- a single flux quantum. Such vortex is therefore called a (Josephson) fluxon. It has been shown that under certain conditions a propagating Josephson vortex can initate another Josephson vortex. This effect is called flux cloning (or fluxon cloning). Although, a second vortex appears, this does not violate the conservation of the single flux quantum.

Recently it was demonstrated by Hilgenkamp et al. that Josephson vortices in the so-called 0-π LJJ can also carry half of the flux quantum, and are called semifluxons.

References

*cite journal
author = H. Hilgenkamp, Ariando, H.-J. H. Smilde, D. H. A. Blank, G. Rijnders, H. Rogalla, J. R. Kirtley and C. C. Tsuei,
title = Ordering and manipulation of the magnetic moments in large-scale superconducting π-loop arrays
journal = Nature (London)
year = 2003
volume = 442
pages = 50

*cite journal
author = D. R. Gulevich and F. V. Kusmartsev,
title = Flux Cloning in Josephson Transmission Lines
journal = Phys. Rev. Lett. | year = 2006
volume = 97
pages = 017004
doi = 10.1103/PhysRevLett.97.017004