The vortex file: A proposal for a new application of type-II superconductivity

Thin-film type-II superconductors are proposed as a new storage medium for future Josephson computers. Vortices in thin films have much in common with magnetic bubbles; storage and propagation can be achieved with a periodic guiding structure and induced transport currents. The packing density was found to be similar to magnetic-bubble density, the maximum vortex shift rate is estimated to be several hundreds of Mbits/sec, being at least two orders of magnitude superior to bubbles. Single-vortex generation and detection schemes are investigated and it is found that the technology bears considerable potential, if thin-film type-II superconductors can be made with sufficiently low pinning forces.