Josephson vortex loops in nanostructured Josephson junctions G.R. Berdiyorov M.V. Milosevic Feodor Kusmartsev F.M. Peeters Sergey Saveliev 2134/28461 https://repository.lboro.ac.uk/articles/journal_contribution/Josephson_vortex_loops_in_nanostructured_Josephson_junctions/9408173 Linked and knotted vortex loops have recently received a revival of interest. Such three-dimensional topological entities have been observed in both classical- and super-fluids, as well as in optical systems. In superconductors, they remained obscure due to their instability against collapse – unless supported by inhomogeneous magnetic field. Here we reveal a new kind of vortex matter in superconductors - the Josephson vortex loops - formed and stabilized in planar junctions or layered superconductors as a result of nontrivial cutting and recombination of Josephson vortices around the barriers for their motion. Engineering latter barriers opens broad perspectives on loop manipulation and control of other possible knotted/linked/entangled vortex topologies in nanostructured superconductors. In the context of Josephson devices proposed to date, the high-frequency excitations of the Josephson loops can be utilized in future design of powerful emitters, tunable filters and waveguides of high-frequency electromagnetic radiation, thereby pushing forward the much needed Terahertz technology. 2018-02-09 13:40:11 Superconducting devices Superconducting properties and materials Physical Sciences not elsewhere classified