Josephson vortex

In superconductivity, a Josephson vortex (after Brian Josephson from Cambridge University) 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. In contrast to Abrikosov vortices in type-II superconductors, a Josephson vortex has a non-superconducting (normal) core.^[1]

Usually the Josephson vortex's supercurrents create a magnetic field with the total flux equal to —a single flux quantum. Such a vortex is therefore called a (Josephson) fluxon. It has been shown that under certain conditions a propagating Josephson vortex can initiate 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.

See also

• Fluxon
• Josephson effect
• Josephson penetration depth
• Long Josephson junction
• Shape waves
• Sine-Gordon equation

References

• H. Hilgenkamp, Ariando, H.-J. H. Smilde, D. H. A. Blank, G. Rijnders, H. Rogalla, J. R. Kirtley and C. C. Tsuei, (2003). "Ordering and manipulation of the magnetic moments in large-scale superconducting π-loop arrays". Nature (London) 422 (6927): 50–3. Bibcode:2003Natur.422...50H. doi:10.1038/nature01442. PMID 12621428. 

• D. R. Gulevich and F. V. Kusmartsev, (2006). "Flux Cloning in Josephson Transmission Lines ". Phys. Rev. Lett. 97 (1): 017004. Bibcode:2006PhRvL..97a7004G. doi:10.1103/PhysRevLett.97.017004. PMID 16907400.