Oscillating rows of vortices in superconductors

Superconductors can be used as dissipation-free electrical conductors as lo ng as vortices are pinned. Vortices in high-temperature superconductors, ho wever, behave anomalously, reflecting the anisotropic layered structure, an d can move readily, thus preventing their practical use. Specifically, in a magnetic field tilted toward the layer plane, a special vortex arrangement (chain-lattice state) is formed. Real-time observation of vortices using h igh-resolution Lorentz microscopy revealed that the images of chain vortice s begin to disappear at a much lower temperature, T-d, than the superconduc ting transition temperature, T-c.. We attribute this image disappearance to the longitudinal oscillation of vortices along the chains.