Fluxon pinning through interaction with the superconducting wiring of   long annular Josephson junctions
  The statics and dynamics of magnetic flux quanta (fluxons) in long annular Josephson tunnel junctions have been investigated. Pinning by interaction of the fluxon field outside the junction with the superconducting wiring has been observed in spatially resolving measurements using low-temperature scanning electron microscopy. We were able to influence the characteristics of this field by carefully modifying the beam-induced fluxon trapping procedure. In this way we were able to select the pinning site acting on the fluxon. 
D. Muenter, T. Doderer, H. Pressler, S. Keil and R. P. Huebener